(2+y)(8-y)=0

Solution for (2+y)(8-y)=0 equation:

(2+y)(8-y)=0

We add all the numbers together, and all the variables

(y+2)(-1y+8)=0

We multiply parentheses ..

(-1y^2+8y-2y+16)=0

We get rid of parentheses

-1y^2+8y-2y+16=0

We add all the numbers together, and all the variables

-1y^2+6y+16=0

a = -1; b = 6; c = +16;
Δ = b2-4ac
Δ = 62-4·(-1)·16
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{-(6)-10}{2*-1}=\frac{-16}{-2}
=+8
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+10}{2*-1}=\frac{4}{-2}
=-2
$