20+(y-10)4y=10

Solution for 20+(y-10)4y=10 equation:

20+(y-10)4y=10

We move all terms to the left:

20+(y-10)4y-(10)=0

We add all the numbers together, and all the variables

(y-10)4y+10=0

We multiply parentheses

4y^2-40y+10=0

a = 4; b = -40; c = +10;
Δ = b2-4ac
Δ = -402-4·4·10
Δ = 1440
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:

$\sqrt{\Delta}=\sqrt{1440}=\sqrt{144*10}=\sqrt{144}*\sqrt{10}=12\sqrt{10}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-40)-12\sqrt{10}}{2*4}=\frac{40-12\sqrt{10}}{8}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-40)+12\sqrt{10}}{2*4}=\frac{40+12\sqrt{10}}{8}
$