Question

Follow the process of completing the square to solve x2 - 10x + 8 = 0.

How will the left side of the equation factor in step 5?

a. (x - 10)2
b. (x - 20)2
c. (2x - 10)2

Answer 1

(2x-10)^2

Explanation:

Follow the process of completing the square to solve x^2 - 10x + 8 = 0

First we subtract 8 from both sides

x^2 - 10x = -8

In completing the square method we take half of coefficient of middle temr -10x and then we square it

-10/2 = -5

(-5)^2= 25

Now we add 25 on both sides

x^2 - 10x +25 = -8+ 25

x^2 - 10x +25 = 17

Now we factor the left hand side x^2 -10x+25

We take half of middle term -10/2

(x-10/2)^2 that is (2x-10)^2

So the left hand side of the equation factor is (2x-10)^2