80r^2-45=0

Solution for 80r^2-45=0 equation:

80r^2-45=0

a = 80; b = 0; c = -45;
Δ = b2-4ac
Δ = 02-4·80·(-45)
Δ = 14400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{14400}=120$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-120}{2*80}=\frac{-120}{160}
=-3/4
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+120}{2*80}=\frac{120}{160}
=3/4
$