1.
1) 12с²+5а³-29а³-13с²=-24а³-с²
2)8b³-3b³+17b-3b³-8b-5=2b³+9b-5
3)5a²+3a-7-5a³-3a²+7a-11=-5a³+2a²+10a-18
4)9х²-8ху-6у²-12х²-ху=-6у²-3х²-9ху
5)6a²b-5ab²+5a³+2ab²-8a³-3a²b=-3a³+3a²b-3ab²
2.
1)(2х+у - z) +(x+2y-2z) =2x+y-z+x+2y-2z=3x+3y-3z
2)(15m³+n²-m) +(2mx-n²-5m³)=15m³+n²-m+2mx-n²-5m³=10m³-m+2mx
3)(6x²-y²+3z²)-(4x²-y²+5z²)=6x²-y²+3z²-4x²+y²-5z²=2x²-2z²
4)(3m-2n²+2ya) -(2m+n²-2ya) =3m-2n²+2ya-2m -n² + 2ya=-3n²+m+4ya
5)(4c²a-2ca²)+(-6c²a+2ca²)=4c²a -2ca²-6c²a+2ca²=-2c²a