-2(7b+5)b=-130

Solution for -2(7b+5)b=-130 equation:

-2(7b+5)b=-130

We move all terms to the left:

-2(7b+5)b-(-130)=0

We add all the numbers together, and all the variables

-2(7b+5)b+130=0

We multiply parentheses

-14b^2-10b+130=0

a = -14; b = -10; c = +130;
Δ = b2-4ac
Δ = -102-4·(-14)·130
Δ = 7380
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{7380}=\sqrt{36*205}=\sqrt{36}*\sqrt{205}=6\sqrt{205}$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-6\sqrt{205}}{2*-14}=\frac{10-6\sqrt{205}}{-28}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+6\sqrt{205}}{2*-14}=\frac{10+6\sqrt{205}}{-28}
$