(8y-7)(7y-8)=0

Solution for (8y-7)(7y-8)=0 equation:

(8y-7)(7y-8)=0

We multiply parentheses ..

(+56y^2-64y-49y+56)=0

We get rid of parentheses

56y^2-64y-49y+56=0

We add all the numbers together, and all the variables

56y^2-113y+56=0

a = 56; b = -113; c = +56;
Δ = b2-4ac
Δ = -1132-4·56·56
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-113)-15}{2*56}=\frac{98}{112}
=7/8
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-113)+15}{2*56}=\frac{128}{112}
=1+1/7
$