7x^2+63x-63=0

Solution for 7x^2+63x-63=0 equation:

7x^2+63x-63=0

a = 7; b = 63; c = -63;
Δ = b2-4ac
Δ = 632-4·7·(-63)
Δ = 5733
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:

$\sqrt{\Delta}=\sqrt{5733}=\sqrt{441*13}=\sqrt{441}*\sqrt{13}=21\sqrt{13}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(63)-21\sqrt{13}}{2*7}=\frac{-63-21\sqrt{13}}{14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(63)+21\sqrt{13}}{2*7}=\frac{-63+21\sqrt{13}}{14}
$