1)3xy²-5xy²-x²y+5x³y=

[tex][−2xy2−x {}^{2} y+5x {}^{3} y[/tex]

2)5z-2z+10z=

[tex]13z[/tex]

3)3a²-5a³+7a²-2a³=

[tex]−7a {}^{3} +4a ^{2} [/tex]

4) 2xy.2xy=

[tex]4x {}^{2} y {}^{2} [/tex]

5) 7x².5x³=

[tex]35x {}^{5} [/tex]

6)(-2x³y⁴).(-3x³y²)=

[tex]6x {}^{6} y {}^{6} [/tex]