x^2-1.2x=11.2

Solution for x^2-1.2x=11.2 equation:

x^2-1.2x=11.2

We move all terms to the left:

x^2-1.2x-(11.2)=0

We add all the numbers together, and all the variables

x^2-1.2x-11.2=0

a = 1; b = -1.2; c = -11.2;
Δ = b2-4ac
Δ = -1.22-4·1·(-11.2)
Δ = 46.24
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1.2)-\sqrt{46.24}}{2*1}=\frac{1.2-\sqrt{46.24}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.2)+\sqrt{46.24}}{2*1}=\frac{1.2+\sqrt{46.24}}{2}
$