Question

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

Answer 1

3x^2 + 18x + 15 = 0
15 + 18x + 3x2 = 0
3(5 + 6x + x2) = 0
3((5 + x)(1 + x)) = 0
5 + x = 0
5 + -5 + x = 0 + -5 Combine like terms: 5 + -5 = 0 0 + x = 0 + -5 x = 0 + -5
x = -5
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1 + x = 0 x=-1
-5,-1