X^2 = 8x - 15

...

Answer: x = 5

Step-by-step explanation: Lets solve by completing the square.

You first need to get - 15 by itself.

x^2-8x=15 Now you need to complete the square my finding a perfect constant that will go with x^2-8x, then add it to the other side containing - 15 to balance the equation out.

-8x/2 = - 4^2=16 This will be the perfect square.

x^2-8x+16 = - 15 + 16

(x-4) ^2 = 1 factor into a binomial, then use the square root on both sides.

√ x-4 ^ 2 = √ 1

x-4 = 1

x=5