7x^2+6x-136=0

Solution for 7x^2+6x-136=0 equation:

7x^2+6x-136=0

a = 7; b = 6; c = -136;
Δ = b2-4ac
Δ = 62-4·7·(-136)
Δ = 3844
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3844}=62$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(6)-62}{2*7}=\frac{-68}{14}
=-4+6/7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+62}{2*7}=\frac{56}{14}
=4
$