Question

Solve the quadratic equation by completing the square.

Answer 1

X^2 - 10x + 15 = 0
x^2 - 10x = -15
x^2 - 10x + 25 = -15 + 25
(x - 5)^2 = 10 <====
x - 5 = (+-)sqrt 10
x = 5 (+-) sqrt 10

solutions are :
x = 5 + sqrt 10 and x = 5 - sqrt 10