(9y+2)(8y-5)=0

Solution for (9y+2)(8y-5)=0 equation:

(9y+2)(8y-5)=0

We multiply parentheses ..

(+72y^2-45y+16y-10)=0

We get rid of parentheses

72y^2-45y+16y-10=0

We add all the numbers together, and all the variables

72y^2-29y-10=0

a = 72; b = -29; c = -10;
Δ = b2-4ac
Δ = -292-4·72·(-10)
Δ = 3721
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3721}=61$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-29)-61}{2*72}=\frac{-32}{144}
=-2/9
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-29)+61}{2*72}=\frac{90}{144}
=5/8
$