0=4b^2-28b-32

Solution for 0=4b^2-28b-32 equation:

0=4b^2-28b-32

We move all terms to the left:

0-(4b^2-28b-32)=0

We add all the numbers together, and all the variables

-(4b^2-28b-32)=0

We get rid of parentheses

-4b^2+28b+32=0

a = -4; b = 28; c = +32;
Δ = b2-4ac
Δ = 282-4·(-4)·32
Δ = 1296
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1296}=36$
$b_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-36}{2*-4}=\frac{-64}{-8}
=+8
$
$b_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+36}{2*-4}=\frac{8}{-8}
=-1
$