-7x^2-11=-123

Solution for -7x^2-11=-123 equation:

-7x^2-11=-123

We move all terms to the left:

-7x^2-11-(-123)=0

We add all the numbers together, and all the variables

-7x^2+112=0

a = -7; b = 0; c = +112;
Δ = b2-4ac
Δ = 02-4·(-7)·112
Δ = 3136
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3136}=56$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-56}{2*-7}=\frac{-56}{-14}
=+4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+56}{2*-7}=\frac{56}{-14}
=-4
$