(2-y)(5y-7)=0

Solution for (2-y)(5y-7)=0 equation:

(2-y)(5y-7)=0

We add all the numbers together, and all the variables

(-1y+2)(5y-7)=0

We multiply parentheses ..

(-5y^2+7y+10y-14)=0

We get rid of parentheses

-5y^2+7y+10y-14=0

We add all the numbers together, and all the variables

-5y^2+17y-14=0

a = -5; b = 17; c = -14;
Δ = b2-4ac
Δ = 172-4·(-5)·(-14)
Δ = 9
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9}=3$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(17)-3}{2*-5}=\frac{-20}{-10}
=+2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(17)+3}{2*-5}=\frac{-14}{-10}
=1+2/5
$