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

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

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

We add all the numbers together, and all the variables

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

We multiply parentheses ..

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

We get rid of parentheses

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

We add all the numbers together, and all the variables

-5y^2+3y+14=0

a = -5; b = 3; c = +14;
Δ = b2-4ac
Δ = 32-4·(-5)·14
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-17}{2*-5}=\frac{-20}{-10}
=+2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+17}{2*-5}=\frac{14}{-10}
=-1+2/5
$