5b^2+20b-70=5

Solution for 5b^2+20b-70=5 equation:

5b^2+20b-70=5

We move all terms to the left:

5b^2+20b-70-(5)=0

We add all the numbers together, and all the variables

5b^2+20b-75=0

a = 5; b = 20; c = -75;
Δ = b2-4ac
Δ = 202-4·5·(-75)
Δ = 1900
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:

$\sqrt{\Delta}=\sqrt{1900}=\sqrt{100*19}=\sqrt{100}*\sqrt{19}=10\sqrt{19}$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-10\sqrt{19}}{2*5}=\frac{-20-10\sqrt{19}}{10}
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+10\sqrt{19}}{2*5}=\frac{-20+10\sqrt{19}}{10}
$