Question

Solve 3x2+48x−12=0 by completing the square.

Answer 1

Explanation:

3x²+48x-12=0

divide everithing by 3

x²+16x-4 =0

(a+b)² = a²+ 2ab+ b²

so a=1, 2ab=2*1*b=2b=16 =2*8 therefore b=8

(x+8)²-4 -64 = 0 (make sure you take away the b²=64)

(x+8)² = 68

√(x+8)² = √68

x+8 = ±2√17

x= -8±2√17