-2x^2*(2x+3)>0
1) Let's solve in ℝ: -2x2·(2x + 3) > 0
We study the sign of each factor of the product
⇥x2 is an even power: it is positive or zero and is zero only at x = 0
⇥Its coefficient, -2, being negative, the expression -2x2 is zero at x = 0 and negative otherwise
⇥The expression 2x + 3 is zero at:
⇥ x = -32
⇥Its coefficient of x, 2, being positive, it is negative before and positive after -32
2) Let's draw up the sign table:
x-∞ -32 0 +∞
-2x2--0-
2x + 3-0++
-2x2·(2x + 3)+0-0-
▶Solution found: x < -32
3) The numeric value of: x < -32 equals:
▷ x < -1.5