Related Post: 2 1 M )+ 3 M 4 1 2 M 3 4 M M 2.5 M 1 2 M 2 3 M 4 7 1 2 M 3 4 F M 1 M 2 M 3 M 4 Reason 2 3 M 7 ) 1 4 M 9 M 2 1 5 M 3 1 4 M 2 M 1 )- 3 M 1 )= 2 1 4m − 2 1 − 2 3 M M 4 )+ 3m 2 M )/ 2 2m 1 )/ 3 M 2 )/ 4