0=7x^2-16x-8

Solution for 0=7x^2-16x-8 equation:

0=7x^2-16x-8

We move all terms to the left:

0-(7x^2-16x-8)=0

We add all the numbers together, and all the variables

-(7x^2-16x-8)=0

We get rid of parentheses

-7x^2+16x+8=0

a = -7; b = 16; c = +8;
Δ = b2-4ac
Δ = 162-4·(-7)·8
Δ = 480
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:

$\sqrt{\Delta}=\sqrt{480}=\sqrt{16*30}=\sqrt{16}*\sqrt{30}=4\sqrt{30}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-4\sqrt{30}}{2*-7}=\frac{-16-4\sqrt{30}}{-14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+4\sqrt{30}}{2*-7}=\frac{-16+4\sqrt{30}}{-14}
$