Respuesta :

Answer:

7+5+12+2+9+2+3=40mn

Answer:

4mn - 6

Step-by-step explanation:

expressions => (-7mn) + 5, 9mn - 8, -2mn - 3

In addition, we get..... (-7mn + 9mn - 2mn) + (-3 - 8 + 5)

4mn + (-6)

=> 4mn - 6

Hope it helps.