(2w+2)w=70

Solution for (2w+2)w=70 equation:

(2w+2)w=70

We move all terms to the left:

(2w+2)w-(70)=0

We multiply parentheses

2w^2+2w-70=0

a = 2; b = 2; c = -70;
Δ = b2-4ac
Δ = 22-4·2·(-70)
Δ = 564
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{564}=\sqrt{4*141}=\sqrt{4}*\sqrt{141}=2\sqrt{141}$
$w_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{141}}{2*2}=\frac{-2-2\sqrt{141}}{4}
$
$w_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{141}}{2*2}=\frac{-2+2\sqrt{141}}{4}
$