8r^2-168=32r

Solution for 8r^2-168=32r equation:

8r^2-168=32r

We move all terms to the left:

8r^2-168-(32r)=0

a = 8; b = -32; c = -168;
Δ = b2-4ac
Δ = -322-4·8·(-168)
Δ = 6400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6400}=80$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-32)-80}{2*8}=\frac{-48}{16}
=-3
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-32)+80}{2*8}=\frac{112}{16}
=7
$