-6x(2x-5)=-12x-30

Solution for -6x(2x-5)=-12x-30 equation:

-6x(2x-5)=-12x-30

We move all terms to the left:

-6x(2x-5)-(-12x-30)=0

We multiply parentheses

-12x^2+30x-(-12x-30)=0

We get rid of parentheses

-12x^2+30x+12x+30=0

We add all the numbers together, and all the variables

-12x^2+42x+30=0

a = -12; b = 42; c = +30;
Δ = b2-4ac
Δ = 422-4·(-12)·30
Δ = 3204
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{3204}=\sqrt{36*89}=\sqrt{36}*\sqrt{89}=6\sqrt{89}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(42)-6\sqrt{89}}{2*-12}=\frac{-42-6\sqrt{89}}{-24}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(42)+6\sqrt{89}}{2*-12}=\frac{-42+6\sqrt{89}}{-24}
$