4a^6+12a^3b^5+9b^10
2а+3b)(2a-3b)=4a^2-6ab+6ab-9b^2=4a^2-9b^2
4a(a-2)-(a-5)^3=4a^2-8a-(a^3-3a^2*5+3*(5)^2*a-(5)^3)=4a^2-8a-a^3+15a^2-75a+75=
=75+19a^2-83a-a^3
Объяснение:
