Question

9(1+3m-n)+6n-15m+4(2-M+3n)+4n

Answer 1

9(1+3m-n)+6n-15m+4(2-M+3n)+4n =

= 9 + 27m - 9n + 6n - 15m + 8 - 4M + 12n + 4n = 
   --               X     X               --      Y      X       X

we reduce similar words (I marked them further)

= 17 + 12m + 13n - 4M    

answer  12m + 13n - 4m + 17
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