-9x^2-36x-40=-6x^2-21x-22

Solution for -9x^2-36x-40=-6x^2-21x-22 equation:

-9x^2-36x-40=-6x^2-21x-22

We move all terms to the left:

-9x^2-36x-40-(-6x^2-21x-22)=0

We get rid of parentheses

-9x^2+6x^2+21x-36x+22-40=0

We add all the numbers together, and all the variables

-3x^2-15x-18=0

a = -3; b = -15; c = -18;
Δ = b2-4ac
Δ = -152-4·(-3)·(-18)
Δ = 9
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9}=3$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-15)-3}{2*-3}=\frac{12}{-6}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-15)+3}{2*-3}=\frac{18}{-6}
=-3
$