-4r(r+6)=-79

Solution for -4r(r+6)=-79 equation:

-4r(r+6)=-79

We move all terms to the left:

-4r(r+6)-(-79)=0

We add all the numbers together, and all the variables

-4r(r+6)+79=0

We multiply parentheses

-4r^2-24r+79=0

a = -4; b = -24; c = +79;
Δ = b2-4ac
Δ = -242-4·(-4)·79
Δ = 1840
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1840}=\sqrt{16*115}=\sqrt{16}*\sqrt{115}=4\sqrt{115}$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-24)-4\sqrt{115}}{2*-4}=\frac{24-4\sqrt{115}}{-8}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-24)+4\sqrt{115}}{2*-4}=\frac{24+4\sqrt{115}}{-8}
$