x^2+2x=1.1

Solution for x^2+2x=1.1 equation:

x^2+2x=1.1

We move all terms to the left:

x^2+2x-(1.1)=0

We add all the numbers together, and all the variables

x^2+2x-1.1=0

a = 1; b = 2; c = -1.1;
Δ = b2-4ac
Δ = 22-4·1·(-1.1)
Δ = 8.4
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{-(2)-\sqrt{8.4}}{2*1}=\frac{-2-\sqrt{8.4}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+\sqrt{8.4}}{2*1}=\frac{-2+\sqrt{8.4}}{2}
$