2x^2+21=127

Solution for 2x^2+21=127 equation:

2x^2+21=127

We move all terms to the left:

2x^2+21-(127)=0

We add all the numbers together, and all the variables

2x^2-106=0

a = 2; b = 0; c = -106;
Δ = b2-4ac
Δ = 02-4·2·(-106)
Δ = 848
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:

$\sqrt{\Delta}=\sqrt{848}=\sqrt{16*53}=\sqrt{16}*\sqrt{53}=4\sqrt{53}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-4\sqrt{53}}{2*2}=\frac{0-4\sqrt{53}}{4}
=-\frac{4\sqrt{53}}{4}
=-\sqrt{53}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+4\sqrt{53}}{2*2}=\frac{0+4\sqrt{53}}{4}
=\frac{4\sqrt{53}}{4}
=\sqrt{53}
$