7x2+16x-20=0

Solution for 7x2+16x-20=0 equation:

7x^2+16x-20=0

a = 7; b = 16; c = -20;
Δ = b2-4ac
Δ = 162-4·7·(-20)
Δ = 816
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:

$\sqrt{\Delta}=\sqrt{816}=\sqrt{16*51}=\sqrt{16}*\sqrt{51}=4\sqrt{51}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-4\sqrt{51}}{2*7}=\frac{-16-4\sqrt{51}}{14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+4\sqrt{51}}{2*7}=\frac{-16+4\sqrt{51}}{14}
$