Y=5r^2+10r

Solution for Y=5r^2+10r equation:

=5Y^2+10Y

We move all terms to the left:

-(5Y^2+10Y)=0

We get rid of parentheses

-5Y^2-10Y=0

a = -5; b = -10; c = 0;
Δ = b2-4ac
Δ = -102-4·(-5)·0
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-10}{2*-5}=\frac{0}{-10}
=0
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+10}{2*-5}=\frac{20}{-10}
=-2
$