7b(5b+5)=0

Solution for 7b(5b+5)=0 equation:

7b(5b+5)=0

We multiply parentheses

35b^2+35b=0

a = 35; b = 35; c = 0;
Δ = b2-4ac
Δ = 352-4·35·0
Δ = 1225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1225}=35$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(35)-35}{2*35}=\frac{-70}{70}
=-1
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(35)+35}{2*35}=\frac{0}{70}
=0
$