(b+30)(b-35)=0

Solution for (b+30)(b-35)=0 equation:

(b+30)(b-35)=0

We multiply parentheses ..

(+b^2-35b+30b-1050)=0

We get rid of parentheses

b^2-35b+30b-1050=0

We add all the numbers together, and all the variables

b^2-5b-1050=0

a = 1; b = -5; c = -1050;
Δ = b2-4ac
Δ = -52-4·1·(-1050)
Δ = 4225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4225}=65$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-65}{2*1}=\frac{-60}{2}
=-30
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+65}{2*1}=\frac{70}{2}
=35
$