Simplify: (5x2 - 9x + 3) + (4x2 + 4x - 12) (1) 9x2 + 5x - 9
2) 9x2 - 5x + 15
3) 9x² - 5x-9
4) 9x2 - 13x - 9

This is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 4 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 3 terms. this is a rational expression because the denominator contains a variable. this is a polynomial with 5 terms.