15r^2=5r

Solution for 15r^2=5r equation:

15r^2=5r

We move all terms to the left:

15r^2-(5r)=0

a = 15; b = -5; c = 0;
Δ = b2-4ac
Δ = -52-4·15·0
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$r_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-5}{2*15}=\frac{0}{30}
=0
$
$r_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+5}{2*15}=\frac{10}{30}
=1/3
$