(x+3)(9x-2)=0

Solution for (x+3)(9x-2)=0 equation:

(x+3)(9x-2)=0

We multiply parentheses ..

(+9x^2-2x+27x-6)=0

We get rid of parentheses

9x^2-2x+27x-6=0

We add all the numbers together, and all the variables

9x^2+25x-6=0

a = 9; b = 25; c = -6;
Δ = b2-4ac
Δ = 252-4·9·(-6)
Δ = 841
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{841}=29$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(25)-29}{2*9}=\frac{-54}{18}
=-3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(25)+29}{2*9}=\frac{4}{18}
=2/9
$