Jawabanmu

2014-07-17T19:46:17+07:00
A. 4 x 2/7 + 4 x 5/7 
= 4 ( 2/7 + 5/7)
= 4 ( 7/7) = 4.1 = 4

b. 2/5 x 9 + 4/5 x 6
= 18/5 + 24/5 = 42/5 = 8 2/5 = 8,4

c. 3/7 x 9 - 3/7 x 12 
= 3/7 ( 9-12)
= 3/7 ( -3)
= -9/7
= - 1,2857
2014-07-17T20:40:59+07:00
A.)4 2/7 + 4 5/7
=8/7+20/7
=28/7=7
atau
4 2/7+ 4 5/7
4(2/7+5/7)
4.1=4


b.) 2/5 9 +4/5 6
18/5+24/5
42/5=8,4

c.)3/7 9 - 3/7 12
27/7 - 36/7
-9/7=-1,28571
atau
3/7(9-12)
=3/7(-3)
=-9/7
hasil.y sama ji dengan diatas;)