Question

2x^2 +14x < -24

Answer 1

2x^2 + 14x + 24 < 0
x^2 + 7x +12 < 0

The expression equals 0 when
-7 + sqrt(49-48)/2 = -6 = x
-7 - sqrt(49-48)/2 = -8 = x

Your x is must be below -8.
2x^2 +14x < -24 is true when x < -8
 

 

Comments

You forgot to divide by 2.

Answer 2

2(x^2+7x+12)<0

2(x+3)(x+4)<0

+++++          _ _ _ _ _ _ _             ++++++

______ -4 ________________-3__________

between -4 and -3