(3-5y)(8-5y)=0

Solution for (3-5y)(8-5y)=0 equation:

(3-5y)(8-5y)=0

We add all the numbers together, and all the variables

(-5y+3)(-5y+8)=0

We multiply parentheses ..

(+25y^2-40y-15y+24)=0

We get rid of parentheses

25y^2-40y-15y+24=0

We add all the numbers together, and all the variables

25y^2-55y+24=0

a = 25; b = -55; c = +24;
Δ = b2-4ac
Δ = -552-4·25·24
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-55)-25}{2*25}=\frac{30}{50}
=3/5
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-55)+25}{2*25}=\frac{80}{50}
=1+3/5
$