Question

What are the values of x in the equation x-6x + 9= 25?

Answer 1

Answer: x = -2 or x = 8

Explanation:

x^2 - 6x + 9 = 25
x^2 - 6x + 9 - 25 = 0
x^2 - 6x - 16 = 0
(x - 8)(x + 2) = 0

Set:
x - 8 = 0
x = 8

x + 2 = 0
x = -2

Answer 2

Answer: x=8 or x=-2

Step-by-step explanation:

It would be the first option on the test.

You should subtract 25 on both sides to get this equation x^2-6x-16 in order to factor.  There are three multiplication equations to get to the number 16 which is 1*16, 2*8, and 4*4.  1*16 wouldn't work since you would get either 17, 15 or -15, 4*4 would also not work since you would get +/-8 or 0, which would finalize our two numbers 2 and 8.

Since the c value is negative you would need to get one of your numbers negative which would be -8 since -8 + 2 = -6 which would factor out to (x-8)(x+2).  Subtract -8 and 2 for each x values to get 8 and -2.