(3x+2)(3x-5)=0

Solution for (3x+2)(3x-5)=0 equation:

(3x+2)(3x-5)=0

We multiply parentheses ..

(+9x^2-15x+6x-10)=0

We get rid of parentheses

9x^2-15x+6x-10=0

We add all the numbers together, and all the variables

9x^2-9x-10=0

a = 9; b = -9; c = -10;
Δ = b2-4ac
Δ = -92-4·9·(-10)
Δ = 441
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{441}=21$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-21}{2*9}=\frac{-12}{18}
=-2/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+21}{2*9}=\frac{30}{18}
=1+2/3
$