Respuesta :
7x^2 + x - 9 - (3x^2 + 4x - 5)....distribute the negative through the parenthesis
7x^2 + x - 9 - 3x^2 - 4x + 5....now just combine like terms
4x^2 - 3x - 4 <===
7x^2 + x - 9 - 3x^2 - 4x + 5....now just combine like terms
4x^2 - 3x - 4 <===
