(7-3x)(2+5x)=0

Solution for (7-3x)(2+5x)=0 equation:

(7-3x)(2+5x)=0

We add all the numbers together, and all the variables

(-3x+7)(5x+2)=0

We multiply parentheses ..

(-15x^2-6x+35x+14)=0

We get rid of parentheses

-15x^2-6x+35x+14=0

We add all the numbers together, and all the variables

-15x^2+29x+14=0

a = -15; b = 29; c = +14;
Δ = b2-4ac
Δ = 292-4·(-15)·14
Δ = 1681
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1681}=41$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(29)-41}{2*-15}=\frac{-70}{-30}
=2+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(29)+41}{2*-15}=\frac{12}{-30}
=-2/5
$