-4=(x+1)(x-3)

Solution for -4=(x+1)(x-3) equation:

-4=(x+1)(x-3)

We move all terms to the left:

-4-((x+1)(x-3))=0

We multiply parentheses ..

-((+x^2-3x+x-3))-4=0


We calculate terms in parentheses: -((+x^2-3x+x-3)), so:

(+x^2-3x+x-3)

We get rid of parentheses

x^2-3x+x-3

We add all the numbers together, and all the variables

x^2-2x-3

Back to the equation:

-(x^2-2x-3)


We get rid of parentheses

-x^2+2x+3-4=0

We add all the numbers together, and all the variables

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

a = -1; b = 2; c = -1;
Δ = b2-4ac
Δ = 22-4·(-1)·(-1)
Δ = 0
Delta is equal to zero, so there is only one solution to the equation

                              Stosujemy wzór:
$x=\frac{-b}{2a}=\frac{-2}{-2}=1$