## Trending News

Promoted

Mikki.

Lv 4

# Completing the square?

Your supposed to solve for x by completing the square. 3x^2+24x+36<0.

thanks.

### 3 Answers

Relevance

- DavidLv 79 years agoFavorite Answer
3x^2 + 24x < -36

x^2 + 8x < -12

x^2 + 8x + (8/2)^2 < -12 + (8/2)^2

x^2 + 8x + 16 < 4

(x + 4)^2 < 4

x + 4 < ± √4

x + 4 < ± 2

x < -2

x > -6

- Man of SteelLv 69 years ago
divide everything by 3.

x^2+8x+12<0

b/2 = 8/2=4

(b/2)^2=16

(x+4)^2<4

x+4<2 or x+4<-2

x<-2 or x<-6

- Anonymous9 years ago
3(x+4)^2 + 36 < 0 + 42

3(x+4)^2 < 6

(x+4)^2 < 2

-5.4 < x < -2.6

Still have questions? Get your answers by asking now.