x2-12=(x+1)(x-3)

Solution for x2-12=(x+1)(x-3) equation:

x2-12=(x+1)(x-3)

We move all terms to the left:

x2-12-((x+1)(x-3))=0

We add all the numbers together, and all the variables

x^2-((x+1)(x-3))-12=0

We multiply parentheses ..

x^2-((+x^2-3x+x-3))-12=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-x^2+2x+3-12=0

We add all the numbers together, and all the variables

2x-9=0

We move all terms containing x to the left, all other terms to the right

2x=9

x=9/2

x=4+1/2