30=5y(y+6)

Solution for 30=5y(y+6) equation:

30=5y(y+6)

We move all terms to the left:

30-(5y(y+6))=0


We calculate terms in parentheses: -(5y(y+6)), so:

5y(y+6)

We multiply parentheses

5y^2+30y

Back to the equation:

-(5y^2+30y)


We get rid of parentheses

-5y^2-30y+30=0

a = -5; b = -30; c = +30;
Δ = b2-4ac
Δ = -302-4·(-5)·30
Δ = 1500
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{1500}=\sqrt{100*15}=\sqrt{100}*\sqrt{15}=10\sqrt{15}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-30)-10\sqrt{15}}{2*-5}=\frac{30-10\sqrt{15}}{-10}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-30)+10\sqrt{15}}{2*-5}=\frac{30+10\sqrt{15}}{-10}
$