(x+1)(3-x)=3

Solution for (x+1)(3-x)=3 equation:

(x+1)(3-x)=3

We move all terms to the left:

(x+1)(3-x)-(3)=0

We add all the numbers together, and all the variables

(x+1)(-1x+3)-3=0

We multiply parentheses ..

(-1x^2+3x-1x+3)-3=0

We get rid of parentheses

-1x^2+3x-1x+3-3=0

We add all the numbers together, and all the variables

-1x^2+2x=0

a = -1; b = 2; c = 0;
Δ = b2-4ac
Δ = 22-4·(-1)·0
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

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