7x2-12x-14=0

Solution for 7x2-12x-14=0 equation:

7x^2-12x-14=0

a = 7; b = -12; c = -14;
Δ = b2-4ac
Δ = -122-4·7·(-14)
Δ = 536
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:

$\sqrt{\Delta}=\sqrt{536}=\sqrt{4*134}=\sqrt{4}*\sqrt{134}=2\sqrt{134}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-2\sqrt{134}}{2*7}=\frac{12-2\sqrt{134}}{14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+2\sqrt{134}}{2*7}=\frac{12+2\sqrt{134}}{14}
$