Answer:
9x^4 -36
Step-by-step explanation:
see image below:)
Answer:
b
Step-by-step explanation:
If you are looking for the value of N, multiply both sides by 4. The value of N is 4900.
The confidence interval formula is computed by:
Xbar ± Z s/ sqrt (n)
Where:
Xbar is the mean
Z is the z value
S is the standard deviation
N is the number of samples
So our given are:
90% confidence interval with a z value of 1.645
Sample size 40, 45
Mean 180, 179
Standard deviation 2, 4
So plugging that information in the data will give us a
confidence interval:
For 1:
Xbar ± Z s/ sqrt (n)
= 180 ± 1.645 (2 / sqrt (40))
= 180 ± 1.645 (0.316227766)
= 180 ± 0.520194675
= 179.48, 180.52
For 2:
Xbar ± Z s/ sqrt (n)
= 179 ± 1.645 (4 / sqrt (45))
<span>= 179 ± 1.645 (0.596284794)</span>
therefore, the answer is letter b
Answer:
x=4
y=2
Step-by-step explanation:
2x+2y=12
x−y=2
In order to solve by elimination, coefficients of one of the variables must be the same in both equations so that the variable will cancel out when one equation is subtracted from the other.
2x+2y=12,x−y=2
To make 2x and x equal, multiply all terms on each side of the first equation by 1 and all terms on each side of the second by 2.
2x+2y=12,2x+2(−1)y=2×2
Simplify.
2x+2y=12,2x−2y=4
Subtract 2x−2y=4 from 2x+2y=12 by subtracting like terms on each side of the equal sign.
2x−2x+2y+2y=12−4
Add 2x to −2x. Terms 2x and −2x cancel out, leaving an equation with only one variable that can be solved.
2y+2y=12−4
Add 2y to 2y.
4y=12−4
Add 12 to −4.
4y=8
Divide both sides by 4.
y=2
Substitute 2 for y in x−y=2. Because the resulting equation contains only one variable, you can solve for x directly.
x−2=2
Add 2 to both sides of the equation.
x=4
The system is now solved.
x=4,y=2
Correct choice is B) x=4.
