2b^2-4b-63=7

Solution for 2b^2-4b-63=7 equation:

2b^2-4b-63=7

We move all terms to the left:

2b^2-4b-63-(7)=0

We add all the numbers together, and all the variables

2b^2-4b-70=0

a = 2; b = -4; c = -70;
Δ = b2-4ac
Δ = -42-4·2·(-70)
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-4)-24}{2*2}=\frac{-20}{4}
=-5
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4)+24}{2*2}=\frac{28}{4}
=7
$