(5x+3)*(9-7x)=0

Solution for (5x+3)*(9-7x)=0 equation:

(5x+3)(9-7x)=0

We add all the numbers together, and all the variables

(5x+3)(-7x+9)=0

We multiply parentheses ..

(-35x^2+45x-21x+27)=0

We get rid of parentheses

-35x^2+45x-21x+27=0

We add all the numbers together, and all the variables

-35x^2+24x+27=0

a = -35; b = 24; c = +27;
Δ = b2-4ac
Δ = 242-4·(-35)·27
Δ = 4356
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4356}=66$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(24)-66}{2*-35}=\frac{-90}{-70}
=1+2/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(24)+66}{2*-35}=\frac{42}{-70}
=-3/5
$