Jawabanmu

2014-09-10T15:13:06+07:00
(42n+35m+7)- (50m-20n+9)
42n + 20n + 35m - 50m + 7 - 9
62n - 15m -2


4 3 4
2014-09-10T15:17:06+07:00
(42n+35m+7)-(50m-20n+9) = 42n+35m+7-50m+20n-9
                                            = 42n+20n+35m-50m+7-9
                                            = 62n-15m-2
       semoga membantu :)
4 3 4