You can put this solution on YOUR website! x^2-(3x+4)=(x+8)(x-5)
First use foil
x^2-(3x+4)=x^2-5x+8x-40
then combine like terms
x^2-3x-4=x^2+3x-40
now move all x's to one side of the
equation and regular numbers to the other
to make an equation.
x^2-x^2-3x-3x=-40+4
now add or subtract like terms
-9x=-36
now divide -9 to both sides
-9x/-9=-36/-9
x=4
good luck!!!