Jawabanmu

2014-08-10T11:30:08+07:00
A. 9a+12-7a+14 = 2a+26
b.11x²-17x+24-2x²+15x-18=9x²-2x+6
c.28y²+24y-20 - (-20y²+10y-40) = 48y²+14y+20