Question

I need help on learning how to complete squares.

Answer 1

Solve 3x2 + 18x + 15 = 0 by completing the square.

3(x + 3)2 = 6; x = −3 + square root 2, x = −3 − square root 2
3(x + 9)2 = 12; x = −11, x = −7
3(x + 3)2 = 12; x = −5, x = −1
3(x + 9)2 = 228; x = −9 + square root 76, x = −9 − square root 76

Answer 2

solve \[3x ^{2}+18x+15-15 =0-15\]\[3(x^2+6x)=0\]\[3(x^2+(\frac{ 6x }{ 2 })^2+.....)=0-15+.....\]\[3(x^2+6x+9)=-15+27\]\[3(x+3)^2=12\]