Jawabanmu

2014-09-09T19:51:47+07:00
1.2/5-(1/2+3/10)
=2/5(5/10+3/10)
=2/5-8/10
=4/10-810
=-4/10
=-2/5
2.(3/7+4/21)-13/14
=(9/21+4/21)-13/14
=13/21-13/14
=182/294-273/294
=-91/294
2014-09-09T19:56:12+07:00
1. 2/5 - 1/2 + 3/10 =
4/10 - 5/10 + 3/10 =
-1/10 + 3/10 = 
2/10 = 1/5.


2. 3/7 + 4/21 - 13/14 =
21/42 + 8/42 - 52/42 =
29/42 - 52/42 = -23/42