(8x-3)(9x+9)=0

Solution for (8x-3)(9x+9)=0 equation:

(8x-3)(9x+9)=0

We multiply parentheses ..

(+72x^2+72x-27x-27)=0

We get rid of parentheses

72x^2+72x-27x-27=0

We add all the numbers together, and all the variables

72x^2+45x-27=0

a = 72; b = 45; c = -27;
Δ = b2-4ac
Δ = 452-4·72·(-27)
Δ = 9801
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9801}=99$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(45)-99}{2*72}=\frac{-144}{144}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(45)+99}{2*72}=\frac{54}{144}
=3/8
$