(9y+2)(7y-9)=0

Solution for (9y+2)(7y-9)=0 equation:

(9y+2)(7y-9)=0

We multiply parentheses ..

(+63y^2-81y+14y-18)=0

We get rid of parentheses

63y^2-81y+14y-18=0

We add all the numbers together, and all the variables

63y^2-67y-18=0

a = 63; b = -67; c = -18;
Δ = b2-4ac
Δ = -672-4·63·(-18)
Δ = 9025
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9025}=95$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-67)-95}{2*63}=\frac{-28}{126}
=-2/9
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-67)+95}{2*63}=\frac{162}{126}
=1+2/7
$