How do you solve 2x^2 + 32x + 12 = 0 using completing the square?

1 Answer
Jun 24, 2015

I found:
x_1=-8+sqrt(58)
x_2=-8-sqrt(58)

Explanation:

Write it as (dividing by 2):
x^2/2+32/2x+12/2=0
x^2+16x+6=0
x^2+16x=-6
Add and subtract 64:
x^2+16x+64-64=-6
x^2+16x+64=-6+64
(x+8)^2=58
x+8=+-sqrt(58)
x=-8+-sqrt(58)
so:
x_1=-8+sqrt(58)
x_2=-8-sqrt(58)