X^2+14x-140=0

Solution for X^2+14x-140=0 equation:

X^2+14X-140=0

a = 1; b = 14; c = -140;
Δ = b2-4ac
Δ = 142-4·1·(-140)
Δ = 756
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:

$\sqrt{\Delta}=\sqrt{756}=\sqrt{36*21}=\sqrt{36}*\sqrt{21}=6\sqrt{21}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(14)-6\sqrt{21}}{2*1}=\frac{-14-6\sqrt{21}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(14)+6\sqrt{21}}{2*1}=\frac{-14+6\sqrt{21}}{2}
$