8x^2+70X-18=7

Solution for 8x^2+70X-18=7 equation:

8x^2+70x-18=7

We move all terms to the left:

8x^2+70x-18-(7)=0

We add all the numbers together, and all the variables

8x^2+70x-25=0

a = 8; b = 70; c = -25;
Δ = b2-4ac
Δ = 702-4·8·(-25)
Δ = 5700
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:

$\sqrt{\Delta}=\sqrt{5700}=\sqrt{100*57}=\sqrt{100}*\sqrt{57}=10\sqrt{57}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(70)-10\sqrt{57}}{2*8}=\frac{-70-10\sqrt{57}}{16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(70)+10\sqrt{57}}{2*8}=\frac{-70+10\sqrt{57}}{16}
$