(1-y)(5y+8)=0

Solution for (1-y)(5y+8)=0 equation:

(1-y)(5y+8)=0

We add all the numbers together, and all the variables

(-1y+1)(5y+8)=0

We multiply parentheses ..

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

We get rid of parentheses

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

We add all the numbers together, and all the variables

-5y^2-3y+8=0

a = -5; b = -3; c = +8;
Δ = b2-4ac
Δ = -32-4·(-5)·8
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-3)-13}{2*-5}=\frac{-10}{-10}
=1
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-3)+13}{2*-5}=\frac{16}{-10}
=-1+3/5
$