7(2x2)+2=128

Solution for 7(2x2)+2=128 equation:

7(2x^2)+2=128

We move all terms to the left:

7(2x^2)+2-(128)=0

We add all the numbers together, and all the variables

72x^2-126=0

a = 72; b = 0; c = -126;
Δ = b2-4ac
Δ = 02-4·72·(-126)
Δ = 36288
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:

$\sqrt{\Delta}=\sqrt{36288}=\sqrt{5184*7}=\sqrt{5184}*\sqrt{7}=72\sqrt{7}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-72\sqrt{7}}{2*72}=\frac{0-72\sqrt{7}}{144}
=-\frac{72\sqrt{7}}{144}
=-\frac{\sqrt{7}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+72\sqrt{7}}{2*72}=\frac{0+72\sqrt{7}}{144}
=\frac{72\sqrt{7}}{144}
=\frac{\sqrt{7}}{2}
$