Factoring, completing the square, and the quadratic formula | y=x^2−2x−24 (y=0)

Question

1) Given the equation y=x^2−2x−24, solve the equation when y=0 by using each method:

a) Factoring

b) Completing the Square

c) The Quadratic Formula

I've already found the answer to A so that one is least important, however I would appreciate if you maybe give the answer just so I can double check my work. If not that's completely fine. Thank you!!!!

Answer 1

A) x²-2x-24 = (x-6)(x+4) = 0, x = 6,-4

B) for x²+bx+c, a perfect square is (x+b/2)² or (x-1)² = x²-2x+1. So we have to add 1 and subtract 1.

(x-1)² -1 -24 = (x-1)²-25=0

x-1 = ±√25 = ±5

x = 1±5 = 6, -4

C) x = (2±√(4-4(1)(-24)))/2 = (2 ± √100)/2 = 1 ±5 = 6,-4