X2+8x-1440=0

Solution for X2+8x-1440=0 equation:

X2+8X-1440=0

We add all the numbers together, and all the variables

X^2+8X-1440=0

a = 1; b = 8; c = -1440;
Δ = b2-4ac
Δ = 82-4·1·(-1440)
Δ = 5824
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{5824}=\sqrt{64*91}=\sqrt{64}*\sqrt{91}=8\sqrt{91}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-8\sqrt{91}}{2*1}=\frac{-8-8\sqrt{91}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+8\sqrt{91}}{2*1}=\frac{-8+8\sqrt{91}}{2}
$