Jawabanmu

2014-09-03T20:25:00+07:00
2014-09-03T20:27:07+07:00
1. 9x+2+2x-3y-4+8y
= 9x+2x-3y+8y+2-4
= 11x+5y-2

2. 12a-5-9b+25-17a-2b
= 12a-17a-5+25-9b-2b
=-5a+20-11b

3. 25x-17y-8x+12-8y-28
=17x-25y-26