x^2-7x=80+2x^2-98

Solution for x^2-7x=80+2x^2-98 equation:

x^2-7x=80+2x^2-98

We move all terms to the left:

x^2-7x-(80+2x^2-98)=0

We get rid of parentheses

x^2-2x^2-7x-80+98=0

We add all the numbers together, and all the variables

-1x^2-7x+18=0

a = -1; b = -7; c = +18;
Δ = b2-4ac
Δ = -72-4·(-1)·18
Δ = 121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{121}=11$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-7)-11}{2*-1}=\frac{-4}{-2}
=+2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+11}{2*-1}=\frac{18}{-2}
=-9
$