Question

combine like terms ...
-6+7m+11+(-9m)

Answer 1

expanding it first:
-6 + 7m + 11 - 9m
after that, combine all like terms
-6+11+7m -9m
= 4-2m

Answer 2

Oh I see. It helps to expand it first!! Thanks so much!!

Answer 3

yup~almost welcome :)