1)4a^2-6a^2+2ab+3ab+2a^2=5ab
(-2a)^2+5ab+2a^2=5ab
5ab=5ab
2)9x^6-4x^3-x^3+9-8x^6+5x^3=x^6+9
x^6+9=x^6+9
1)4a^2-6a^2+2ab+3ab+2a^2=5ab
(-2a)^2+5ab+2a^2=5ab
5ab=5ab
2)9x^6-4x^3-x^3+9-8x^6+5x^3=x^6+9
x^6+9=x^6+9