20+8y=5y^2

Solution for 20+8y=5y^2 equation:

20+8y=5y^2

We move all terms to the left:

20+8y-(5y^2)=0

determiningTheFunctionDomain
-5y^2+8y+20=0

a = -5; b = 8; c = +20;
Δ = b2-4ac
Δ = 82-4·(-5)·20
Δ = 464
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:

$\sqrt{\Delta}=\sqrt{464}=\sqrt{16*29}=\sqrt{16}*\sqrt{29}=4\sqrt{29}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-4\sqrt{29}}{2*-5}=\frac{-8-4\sqrt{29}}{-10}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+4\sqrt{29}}{2*-5}=\frac{-8+4\sqrt{29}}{-10}
$