(8x+5)(1-9x)=0

Solution for (8x+5)(1-9x)=0 equation:

(8x+5)(1-9x)=0

We add all the numbers together, and all the variables

(8x+5)(-9x+1)=0

We multiply parentheses ..

(-72x^2+8x-45x+5)=0

We get rid of parentheses

-72x^2+8x-45x+5=0

We add all the numbers together, and all the variables

-72x^2-37x+5=0

a = -72; b = -37; c = +5;
Δ = b2-4ac
Δ = -372-4·(-72)·5
Δ = 2809
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2809}=53$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-37)-53}{2*-72}=\frac{-16}{-144}
=1/9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-37)+53}{2*-72}=\frac{90}{-144}
=-5/8
$