Respuesta :

Step-by-step explanation:

5x^2 +5x - x^2 + 3x -7 -12

or, 4x^2 + 8x - 19

This is the solution of this question..

Erlea

Step-by-step explanation:

1st rearrange like terms

5x^2-x^2+5x+3x-7-12

then add/ subtract the rearranged like terms

4x^2+8x+19

finally there's no similar to simplify