-7x^2-25x-12=0

Solution for -7x^2-25x-12=0 equation:

-7x^2-25x-12=0

a = -7; b = -25; c = -12;
Δ = b2-4ac
Δ = -252-4·(-7)·(-12)
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-25)-17}{2*-7}=\frac{8}{-14}
=-4/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-25)+17}{2*-7}=\frac{42}{-14}
=-3
$