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

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

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

We multiply parentheses ..

(+15x^2+25x+27x+45)=0

We get rid of parentheses

15x^2+25x+27x+45=0

We add all the numbers together, and all the variables

15x^2+52x+45=0

a = 15; b = 52; c = +45;
Δ = b2-4ac
Δ = 522-4·15·45
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(52)-2}{2*15}=\frac{-54}{30}
=-1+4/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(52)+2}{2*15}=\frac{-50}{30}
=-1+2/3
$