Jawabanmu

2014-09-02T20:35:53+07:00
(-2x + 7a) + (-13a + 9x)
= (-2x + -9x) + (7a + -13a)
= (-11x) + (-6a)
1 2 1
2014-09-02T20:36:24+07:00
(-2x + 7a ) + (-13a + 9x) = -2x + 7a -13a + 9x = -2x + 9x + 7a - 13a = 7x - 6a

1 5 1