2x^2+4x=2.5

Solution for 2x^2+4x=2.5 equation:

2x^2+4x=2.5

We move all terms to the left:

2x^2+4x-(2.5)=0

We add all the numbers together, and all the variables

2x^2+4x-2.5=0

a = 2; b = 4; c = -2.5;
Δ = b2-4ac
Δ = 42-4·2·(-2.5)
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(4)-6}{2*2}=\frac{-10}{4}
=-2+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(4)+6}{2*2}=\frac{2}{4}
=1/2
$