Jawabanmu

2014-08-25T21:07:22+07:00
= 42n+35m+7-50m+20n-9
=42n+20n+35m-50m+7-9
=62n-15m-2
5 3 5
2014-08-25T21:22:33+07:00
(42n+35m+7)-(50m-20n+9)
= 42n-(-20n)+35m-50m+7-9
=42n+20n+35m-50m+7-9
= 62n-15m-2

semoga membantu :)
5 4 5