-2(r+2)*5r=6r+11

Solution for -2(r+2)*5r=6r+11 equation:

-2(r+2)*5r=6r+11

We move all terms to the left:

-2(r+2)*5r-(6r+11)=0

We multiply parentheses

-10r^2-20r-(6r+11)=0

We get rid of parentheses

-10r^2-20r-6r-11=0

We add all the numbers together, and all the variables

-10r^2-26r-11=0

a = -10; b = -26; c = -11;
Δ = b2-4ac
Δ = -262-4·(-10)·(-11)
Δ = 236
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:

$\sqrt{\Delta}=\sqrt{236}=\sqrt{4*59}=\sqrt{4}*\sqrt{59}=2\sqrt{59}$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-26)-2\sqrt{59}}{2*-10}=\frac{26-2\sqrt{59}}{-20}
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-26)+2\sqrt{59}}{2*-10}=\frac{26+2\sqrt{59}}{-20}
$