Respuesta :

The answer would be 15m + 2n.

1. Gather like terms (8m + 7m) + (4n - 2n)

2. Simplify (15m + 2n)
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8m + 4n + 7m + −2n
*Combine Like Terms:* 
=8m + 4n + 7m + −2n
=(8m + 7m) + (4n + −2n)
Answer: 15m + 2n   

Hope this helps! :)