Simplify 3x^2+6-2x+5x-4x^2+9

Answer 1

3 x² + 6 - 2 x + 5 x - 4 x² + 9 =

3 x² - 4 x² - 2 x + 5 x + 6 + 9 =

- x² + 3 x + 15 = - ( x² - 3 x - 15 )