Jawabanmu

2014-09-02T21:10:35+07:00
A. (x - 5) - (-3x - 4)
= x - 5 + 3x + (-4)
= 4x - 9
b. (5a + 4) - (7a - 5)
= 5a + 4 - 7a + 5
= -2a + 9