(9y+4)(7y+2)=0

Solution for (9y+4)(7y+2)=0 equation:

(9y+4)(7y+2)=0

We multiply parentheses ..

(+63y^2+18y+28y+8)=0

We get rid of parentheses

63y^2+18y+28y+8=0

We add all the numbers together, and all the variables

63y^2+46y+8=0

a = 63; b = 46; c = +8;
Δ = b2-4ac
Δ = 462-4·63·8
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(46)-10}{2*63}=\frac{-56}{126}
=-4/9
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(46)+10}{2*63}=\frac{-36}{126}
=-2/7
$