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

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

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

We multiply parentheses ..

(+4y^2-10y+14y-35)=0

We get rid of parentheses

4y^2-10y+14y-35=0

We add all the numbers together, and all the variables

4y^2+4y-35=0

a = 4; b = 4; c = -35;
Δ = b2-4ac
Δ = 42-4·4·(-35)
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-24}{2*4}=\frac{-28}{8}
=-3+1/2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+24}{2*4}=\frac{20}{8}
=2+1/2
$