5x^2-15x-12x=0

Solution for 5x^2-15x-12x=0 equation:

5x^2-15x-12x=0

We add all the numbers together, and all the variables

5x^2-27x=0

a = 5; b = -27; c = 0;
Δ = b2-4ac
Δ = -272-4·5·0
Δ = 729
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{729}=27$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-27)-27}{2*5}=\frac{0}{10}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-27)+27}{2*5}=\frac{54}{10}
=5+2/5
$