AIUDA PLIS DOY 20 PUNTOS

( SUMAS )

1 : (3×-2y+1)+(2×+5y-6)
2: (4+-3y+13)+(7×+8y-6)
3 : (8a×+2by-7cz)+(2by-3ax-7cz)

( RESTAS )

1 : (5×+6y-8)-(7y-2×-3)
2 : (-14xy-9xy+16xy)-(-10×y+19xy+21xy)
3 : (×+22×-13×)-(-15×-11×+5×)​