15x^2+80x+100=0

Solution for 15x^2+80x+100=0 equation:

15x^2+80x+100=0

a = 15; b = 80; c = +100;
Δ = b2-4ac
Δ = 802-4·15·100
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(80)-20}{2*15}=\frac{-100}{30}
=-3+1/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(80)+20}{2*15}=\frac{-60}{30}
=-2
$