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

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

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

We multiply parentheses ..

(+3x^2-2x+15x-10)=0

We get rid of parentheses

3x^2-2x+15x-10=0

We add all the numbers together, and all the variables

3x^2+13x-10=0

a = 3; b = 13; c = -10;
Δ = b2-4ac
Δ = 132-4·3·(-10)
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(13)-17}{2*3}=\frac{-30}{6}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(13)+17}{2*3}=\frac{4}{6}
=2/3
$