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
