(y-8)(y-8)=4

Solution for (y-8)(y-8)=4 equation:

(y-8)(y-8)=4

We move all terms to the left:

(y-8)(y-8)-(4)=0

We multiply parentheses ..

(+y^2-8y-8y+64)-4=0

We get rid of parentheses

y^2-8y-8y+64-4=0

We add all the numbers together, and all the variables

y^2-16y+60=0

a = 1; b = -16; c = +60;
Δ = b2-4ac
Δ = -162-4·1·60
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-16)-4}{2*1}=\frac{12}{2}
=6
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-16)+4}{2*1}=\frac{20}{2}
=10
$