Answer:
x = 1 + sqrt(89) or x = 1 - sqrt(89)
Step-by-step explanation:
Solve for x:
(x - 9) (x + 7) = 25
Expand out terms of the left hand side:
x^2 - 2 x - 63 = 25
Add 63 to both sides:
x^2 - 2 x = 88
Add 1 to both sides:
x^2 - 2 x + 1 = 89
Write the left hand side as a square:
(x - 1)^2 = 89
Take the square root of both sides:
x - 1 = sqrt(89) or x - 1 = -sqrt(89)
Add 1 to both sides:
x = 1 + sqrt(89) or x - 1 = -sqrt(89)
Add 1 to both sides:
Answer: x = 1 + sqrt(89) or x = 1 - sqrt(89)
Answer:
4x1
Step-by-step explanation:
Answer:
the slope of line j is -1/8, the slope of lines m and n are both 8.
Explanation step by step:
Suppose j is the slope of line j, m the slope of line m and n the slope of line n. Since:
1. line j is perpendicular of line m, so j*m= -1
2. J is perpendicular of line n, so j*n=-1
3. m and n and parallel so m=n
As we want to know the slope of j we clear the equations presented to us in order to find it.
(1) m* n* j = -8, since n=m we have * j = -8.
we clear j;
replacing in the equation n*j = -1 we get
n*(-8/n^2) = -1. Thus n = 8. Since j = -1/n = -1/8.
Answer:
We have to find the 90% confidence interval for the mean
Given sample size
Sample mean
Population standard deviation
Here the confidence level is 90% then
And
The 90% confidence interval is
Here is the critical value at 0.05
From the tables
Now the 90% confidence interval is =
=
=(3840.44, 4133.56)
Hence the 90% confidence interval for the mean is (3840.44, 4133.56)