Jawabanmu

2014-08-06T17:45:52+07:00
-5 x a = -5a
-5 x -3b = 15b
jadi skrg 18a - 5a + 15b = 13a + 15b

wish this helps :)
2014-08-06T17:47:40+07:00

-5 x a = -5a
-5 x -3b = 15b
18a - 5a + 15b = 13a + 15b