Answer:
let 2 no. be x and y
x+y=31 ..... (1)
x-y=11 .........(2)
from (1)
x=31-y ..........(3)
putting (3) in (2)
31-y-y=11
-2y=11-31
-2y=-20
2y=20
y=10
= 10 + 3
=13
Example 6
If f(x) = 2x + 1, g(x) = 3x - 2 and fg(x) = 5, find the value of x,
Answer:
f(x) = 2x + 1, g(x) = 3x - 2 and fg(x) = 5
Step-by-step explanation:
A concert promoter sells tickets and has a marginal-profit function given below, where P'(x) is in dollars per ticket. This means that the rate of
change of total profit with respect to the number of tickets sold, x, is P'(x). Find the total profit from the sale of the first 380 tickets, disregarding any
fixed costs.
P'(x) = 2x - 1198
The total profit is $
Answer:
The answer is "-310840".
Step-by-step explanation:
[tex]\begin{array}{l} P'(x) = 2x - 1198\\ \\ \frac{{dP}}{{dx}} = 2x - 1198\\ \\ dP = \left( {2x - 1198} \right)dx\\ \\ \int {dP} = \int\limits_0^{380} {\left( {2x - 1198} \right)dx} \\ \\ P = \left( {2\frac{{{x^2}}}{2} - 1198x} \right)_0^{380}\\ \\ P = {380^2} - 1198 \times 380 = 144400-455240=-310840\\ \end{array}[/tex]
Two solutions of the equation Ax+By = 1 are (2, -1) and (-3,-2). Find A and B.
Answer:
Substitute in the values of both given coordinates & form 2 equations:
[tex]\left \{ {{A(2)+B(-1)=1} \atop {A(-3)+B(-2)=1}} \right. \\\\=\left \{ {{2A-B=1} \atop {-3A-2B=1}} \right.[/tex]
Find the value of B from the equation 2A - B = 1:
[tex]2A-B=1\\-B=1-2A\\B=2A-1[/tex]
Substitute in the B-value to the other equation:
[tex]-3A-2B=1\\-3A-2(2A-1)=1\\-3A-4A+2=1\\-7A=1-2\\-7A=-1\\A=\frac{-1}{-7} =\frac{1}{7}[/tex]
Find the B-value using the equation from before:
[tex]B=2A-1=2(\frac{1}{7})-1=\frac{2}{7} -\frac{7}{7} =-\frac{5}{7}[/tex]
Therefore the equation Ax + By = 1 would equal:
[tex]\frac{1}{7} x-\frac{5}{7} y=1[/tex]
The point (7, 8) is the solution of which of the following systems of equations?
1. 8x - y = 48
9x + 10y = 142
2. 9x - y = 55
8x + 10y = 140
3. x-6y=-41
8x + 9y = 127
4. x-7y=-49
10x + 9y = 142
Option 4
Verification:-
[tex]\\ \sf\longmapsto x-7y=-49[/tex]
[tex]\\ \sf\longmapsto 7-7(8)=-49[/tex]
[tex]\\ \sf\longmapsto 7-56=-49[/tex]
[tex]\\ \sf\longmapsto -49=-49[/tex]
And
[tex]\\ \sf\longmapsto 10x+9y=142[/tex]
[tex]\\ \sf\longmapsto 10(7)+9(8)=142[/tex]
[tex]\\ \sf\longmapsto 70+72=142[/tex]
[tex]\\ \sf\longmapsto 142+142[/tex]
Hence verified
Answer:
4.
Step-by-step explanation:
1. 8x - y = 48
9x + 10y = 142
8(7) - 8 = 48
9(7) + 10(8) = 143
No
2. 9x - y = 55
8x + 10y = 140
9(7) - 8 = 55
9(7) - 10(7) = -24
No
3. x-6y=-41
8x + 9y = 127
7 - 6(8) = -41
8(7) + 9(8) = 128
No
4. x-7y=-49
10x + 9y = 142
7 - 7(8) = 49
10(7) + 9(8) = 142
Yes
Algebra two divide plz help
Answer:
- x³ - 2x² + 3 - 1 / x
Step-by-step explanation:
(4x³ - 8x² + 12x - 4) / (-4x)
- x³ - 2x² + 3 - 1 / x
Which one is the intersection point of
f(x) = x3 + 3x and
g(x) = x2 + 3
A) (0,0)
B) (0,3)
C) (1,4)
D) (-1,4)
I URGENTLY NEED HELP PLEASE , I WOULD ALSO MARK AS BRAINLIEST!!
Answer: C) (1,4)
Step-by-step explanation:
The intersection point is where f(x) = g(x)
x³ + 3x = x² + 3
x³ - x² +3x - 3 = 0
A. (0, 0) → x = 0 → (0)³ - (0)² +3(0) - 3 = -3 ≠ 0B. (0, 3) → x = 0 → (0)³ - (0)² +3(0) - 3 = -3 ≠ 0C. (1, 4) → x = 1 → (1)³ - (1)² +3(1) - 3 = 0 + 0 = 0D. (-1, 4) → x = -1 → (-1)³ - (-1)² +3(-1) - 3 = 0 - 3 - 3 = -6 ≠ 0which graph correctly represents this 2y+x=-5and y+3x=0
Answer:
you didn't feature any graphs for me to choose from
perimeter of a circle 8 centimeter wide
Answer:
25.13 cm
Step-by-step explanation:
Perimeter ( circumference ) of a circle = 2πr
Given,
The circle is 8 cm wide
which means,
The diameter (d) of the circle is 8 cm.
Radius (r) of the circle = d/2
= 8/2
= 4
Radius = 4 cm
Putting the value in the formula;
2πr
= 2 (22/7) (4)
= 25.13 cm (approx)
identify an equation in point slope form for the line perpendicular to y=5x=2 that passes through (-6,-1)
Answer:
y=-1/5x-11/5
Step-by-step explanation:
perpendicular, product of both gradients = -1
hence, slope = -1/5
y=-1/5x+c
sub y=-1, x=-6
-1=-1/5(-6)+c
c = -1-6/5=-11/5
y=-1/5x-11/5
Select the correct answer.
What is the value of this expression when x = -6 and ?
4(x2 + 3) − 2y
Answer:
D. 157
Step-by-step explanation:
4(x^2+3)-2y
4(6^2+3)-2(-1/2) add in given values
4(39)+1. start with parentheses
156+1. combine like terms
157. answer
Answer:
D. 157
Step-by-step explanation:
Hi there!
We want to find the value of the expression 4(x²+3)-2y is when x=-6 and y=-1/2
Let's first simplify the expression, as that will likely make it easier
Distribute 4 to both x² and 3
4x²+12-2y
That's the expression
Substitute -6 as x into the expression
4(-6)²+12-2y
Raise (-6) to the second power
4*36+12-2y
Multiply 36 by 4
144+12-2y
Add 12 and 144 together
156-2y
Now the expression is 156-2y
But remember that we know that y=-1/2, and we haven't substituted it into the expression yet
Substitute -1/2 as y into the expression
156-2(-1/2)
Multiply
156+2/2
Simplify
156+1
Add
157
Hope this helps!
A person's email for one day contained a total of 78 messages. The number of spam
messages was two less than four times the number of other messages. How many of
the email messages were spam?
Answer:
62 of the email messages were spam
Step-by-step explanation:
Let the number of spam and other messages be s and o respectively.
Total number of messages= 78
s +o= 78 -----(1)
s= 4o -2 -----(2)
Substitute (2) into (1):
4o -2 +o= 78
Simplify:
5o -2= 78
+2 on both sides:
5o= 78 +2
5o= 80
Divide both sides by 5:
o= 80 ÷5
o= 16
Since s +o= 78, s= 78 -o.
s= 78 -16
s= 62
Identify the pair numbers
Answer:
D. 212 degrees Fahrenheit and 100 degrees Celsius.
Step-by-step explanation:
The boiling point of water in Celsius is 100.
The way to calculate Celsius to Fahrenheit:
F = (C × 9/5) + 32
So we plug in 100 for C.
F = (100 × 9/5) + 32
F = 180 + 32
F = 212
Therefore, the numbered pair is 212 degrees F and 100 degrees C.
4. (08.02 MC)
Factor completely 2x3 + 10x2 + 14x + 70. (5 points)
(2x^2 + 14)(x + 5)
(x^2 + 7)(2x + 10)
2(x^3 + 5x2 + 7x + 35)
2[(x^2 + 7)(x + 5)]
Answer:
2[(x^2 + 7)(x + 5)]
Step-by-step explanation:
Note that the ratio of the first and second terms is the same as that between the third and fourth terms. So this cubic will factor by grouping, but first we can separate out the common scalar factor 2...
2x3+10x2+14x+70=
2(x3+5x2+7x+35)
2((x3+5x2)+(7x+35))
2(x2(x+5)+7(x+5))
2(x2+7)(x+5)
Answer:
The answer is D. 2[(x2 + 7)(x + 5)]
Step-by-step explanation:
find the missing length indicated
Answer:
192
Step-by-step explanation:
geometric mean theorem :
with p and q being the segments of the Hypotenuse, then
h = x = sqrt(p×q)
p = 144
q = 400-144 = 256
h = x = sqrt(144×256) = 12×16 = 192
Please helps fill in the charts
A and b
With order of pairs
Answer:
...
Step-by-step explanation:
seeee the above picture
Find the most general antiderivative of the function. (Check your answer by differentiation. Use C for the constant of the antiderivative. Remember to use absolute values where appropriate.)
f(x) = 45−5x, x>0 .
Answer:
F(x) = 45*x - (5/2)*x^2 + C
Step-by-step explanation:
Here we want to find the antiderivative of the function:
f(x) = 45 - 5*x
Remember the general rule that, for a given function:
g(x) = a*x^n
the antiderivative is:
G(x) = (a/(n + 1))*a*x^(n + 1) + C
where C is a constant.
Then for the case of f(x) we have:
F(x) = (45/1)*x^1 - (5/2)*x^2 + C
F(x) = 45*x - (5/2)*x^2 + C
Now if we derivate this, we get:
dF(x)/dx = 1*45*x^0 - 2*(5/2)*x
dF(x)/dx = 45 - 5*x
What is the value of x?
2
3
6
7
Answer:
i think 3
Step-by-step explanation:
Answer: [A] 2
Step-by-step explanation:
100% on edge 2023
(SAT PREP) Find the value of x in each of the following excersises
Answer:
The answer is 155.
Step-by-step explanation:
We can find the remaining parts of the triangle angles.
I'm stuck. Can anyone help please?
log₉(x - 7) + log₉(x - 7) = 1
2 log₉(x - 7) = 1
log₉(x - 7) = 1/2
Take the base-9 antilogarithm of both sides; in other words, make both sides powers of 9:
[tex]9^{\log_9(x-7)} = 9^{1/2}[/tex]
[tex]9^{1/2}[/tex] can also be written as √9 = 3, and [tex]b^{\log_b(a)}=a[/tex], so the equation reduces to
x - 7 = 3
Solve for x :
x = 10
what number increased by 130% is 69
Answer:
The number is 30.
Step-by-step explanation:
Let the number be x
so
x + (130% of x) = 69
x + 13x/10 = 69
or, (10x + 13x)/10 = 69
or, 23x = 690
or, x = 690/23
so, x = 30
Answer: 30
Step-by-step explanation:
its correct on rsm
Question 26 of 58
Mr. Nguyen recorded the numbers of students in his homeroom class who
participated in spirit week.
The table shows the number of students who dressed up each day.
Day
Mon Tues. Wed. Thurs. Fri. Total
Number of students 2
2
5
5
6
20
Find the mean and the median of the data set.
Determine which of these values is greater.
O A. The mean, 5, is greater than the median, 4.
OB. The mean, 5, is greater than the median, 2.
O c. The median, 6, is greater than the mean, 2.
O D. The median, 5, is greater than the mean, 4.
Answer:
D
Step-by-step explanation:
The answer is D.
find an odd natural numbers x such that LCM (x, 40) = 1400
Answer:
175
Step-by-step explanation:
so, the LCM is the combination of the longest chains of the prime factors in every number.
40 : 2, 2, 2, 5
1400 / 40 = 35
35 : 5, 7
but LCM(35, 40) = 2×2×2×5×7 = 280
and not 1400.
what is missing ?
1400 / 280 = 5
aha, another prime factor 5 is missing to get 1400.
x : 5, 5, 7
so, x = 5×5×7 = 175
LCM(175, 40) = 2×2×2×5×5×7 = 1400
Solve the system of equations.
4x + 3y + 5z = 6
6x + 8y + 6z = 4
4x + 2y + z = 8
(x = 1, y = -1,2 = 1)
b. (x = 3, y = -3,2 = 3)
a.
C. (x = 0, y = 0, 2 = 2)
d. (x - 2, y --2, z = 0)
Help me out with these 2 questions for 15 points.
Step-by-step explanation:
The time dilation formula is given by
[tex]F(t) = \dfrac{t}{\sqrt{1-v^2}}[/tex]
where t is the time measured by the moving observer and F(t) is the time measured by the stationary earth-bound observer and v is the velocity of the moving observer expressed as a fraction of the speed of light.
a) If the observer is moving at 80% of the speed of light and observes an event that lasts for 1 second, a stationary observer will see the same event occurring over a time period of
[tex]F(t) = \dfrac{1\:\text{s}}{\sqrt{1-(0.8)^2}}[/tex]
[tex]\:\:\:\:\:\:\:=\dfrac{1\:\text{s}}{\sqrt{1-(0.8)^2}} =\dfrac{1\:\text{s}}{\sqrt{1-(0.64)}}[/tex]
[tex]\:\:\:\:\:\:\:=1.67\:\text{s}[/tex]
This means that any event observed by this moving observer will be seen by a stationary observer to occur 67% longer.
b) Given:
t = 1 second
F(t) = 2 seconds
We need to find the speed of the observer such that an event seen by this observer will occur twice as long as seen by a stationary observer. Move the term containing the radical to the left side so the equation becomes
[tex]\sqrt{1-v^2} = \dfrac{t}{F(t)}[/tex]
Take the square of both sides, we get
[tex]1 - v^2 =\dfrac{t^2}{F^2(t)}[/tex]
Solving for v, we get
[tex]v^2 = 1 - \dfrac{t^2}{F^2(t)}[/tex]
or
[tex]v = \sqrt{1 - \dfrac{t^2}{F^2(t)}}[/tex]
Putting in the values for t and F(t) we get
[tex]v = \sqrt{1 - \dfrac{(1\:\text{s})^2}{(2\:\text{s})^2}}[/tex]
[tex]v = \sqrt{1 - \dfrac{1}{4}} = \sqrt{0.75}[/tex]
[tex]\:\:\:\:=0.866[/tex]
This means that the observer must moves at 86.6% of the speed of light.
A height of 2.5 cm represents 100 goats. What should be the height for 170 goats?
Answer: 4.25
Step-by-step explanation:
2.5/100 = 0.025
0.025 × 170 = 4.25
but the question there is any goats in 2.5 cm ??
that is impossible
Write a quadratic function f whose zeros are 4 and 1
9514 1404 393
Answer:
f(x) = (x -4)(x -1)
Step-by-step explanation:
If 'a' is a zero of the function, then (x -a) is a factor. The two zeros mean the factored form of the quadratic is ...
f(x) = (x -4)(x -1)
__
The expanded form will be ...
f(x) = x² -5x +4
Which describes the correlation shown in the scatterplot?
On a graph, points are grouped closely together and increase.
There is a positive correlation in the data set.
There is a negative correlation in the data set.
There is no correlation in the data set.
More points are needed to determine the correlation.
Answer:
More points are needed to determine the correlation.
Answer:
its d
Step-by-step explanation:
;)
NEED HELP ASAPPPPP !!!
Answer:
2160
Step-by-step explanation:
because c is 15 and d is 12 therefore d² is 144 and 144x15 is 2160
Answer:
2160
Step-by-step explanation:
Substitute
[tex](15)(12) {}^{2} [/tex]
[tex]15 \times 144 = 2160[/tex]
Determine which type of error is most likely to arise from the following situations. a 1. the time in which individuals are contacted to take a survey occurs during work hours f 2. the last part of a newspaper article asks readers to mail or email the newspaper their opinion about universal health coverage 3. subjects are asked to recall how often they snacked between meals in the past 30 days 4. a survey to assess teachers' opinions about Common Core uses a member list for the largest teachers' union as the sampling frame a. question wording b. undercoverage c. processing error d. bad sampling method e. response error f. nonresponse g. random sampling error
Answer:
Determination of type of error arising from the situations
Situation Type of Error
1. Nonresponse
2. Bad sampling method
3. Question wording
4. Undercoverage
Step-by-step explanation:
Types of errors:
a. question wording means that the manner a question is worded elicits some particular responses, which may not accurately reflect reality.
b. undercoverage occurs when some elements of the target population is not represented on the survey frame.
c. processing error arises from data processing
d. bad sampling method is caused by the voluntariness of those who choose to respond.
e. response error is caused by a questionnaire that requires framing improvements, misinterpretation of questions by interviewers or respondents, and errors in respondents' statements.
f. nonresponse error arises as a result of incomplete information or partial response.
g. random sampling error arises from the limited sample size when compared with the population size.
An education researcher would like to test whether 2nd graders retain or lose knowledge during the summer when they are presumably not in school. She asks nine 2nd graders to take a comprehension exam at the end of the school year (May), and then asks those same students to come back after the summer (late August) to retake a different but equivalent exam, to see if their level of comprehension has changed. Using the data below, test this hypothesis using an (alpha level of 0.05.)
May August
95 100
72 80
78 95
50 65
89 85
92 98
75 70
90 96
65 87
Required:
What is the appropirate test?
Answer:
Kindly check explanation
Step-by-step explanation:
Given the data:
May August
95 100
72 80
78 95
50 65
89 85
92 98
75 70
90 96
65 87
The appropriate test is a paired t test :
d = difference between May and August
d = (-5, -8, -17, -15, 4, -6, 5, -6, -22)
The hypothesis :
H0 : μd = 0
H1 : μd ≠ 0
The test statistic :
T = dbar / (Sdbar/√n)
Where, dbar and Sdbar are the mean and standard deviation of 'd' respectively.
Using calculator :
dbar = - 7.777 ; Sdbar = 9.052
Test statistic = - 7.777 / (9.052 /√9)
Test statistic = - 2.577
The Pvalue, df = n - 1 = 9 - 1 = 8
Pvalue(-2.577, 8) = 0.0327
At α = 0.05
Pvalue < α ; WE reject the H0 ; and conclude that there has been a change in score
