simplify (3x^2-5x+4)-(5x^2+7x-7)
Combine similar terms. For example, the two "x^2" terms combine to give
3x^2 -5x^2 = -2x^2
You can also combine the two 'x' terms, to get one 'x' term and the two constants also.
Don't forget that the "-" in front of
(5x^2+7x-7) changes the sign of every term inside the parentheses, before you combine similar terms.
You should end up with
-2x^2 -12x +11