Question

complete the square to solve the following quadratic equation: x^2 - 6x - 20 = 20
x = 3+2squared10, x = 3-2squared10
x = -10, x = 4
x = 52, x = 46
x = 10, x = 4

Answer 1

Start with
x^2 - 6x - 20 = 20
Move 20 to the left:
x^2 - 6x - 40 = 0
Complete the square (or move constant to right first):
x^2 - 6x = 40
Add (6/2)^2 = 9 to both sides:
(x - 3)^2 = 49
Take square roots:
x - 3 = ±7
So x = 3 ± 7, giving x = 10 or x = -4.

None of the provided choices match exactly (the closest "x = 10, x = 4" has the sign wrong for the second root).