①5a^2b÷(-1/3ab)*(2ab^2)^2 =-15a×4a^2b^4=-60a^3b^4②（3a^2b-4ab^2-5ab-1）(-2ab^2)=-6a^3b^3+8a^2b^4+10a^2b^3+2ab^2③（3x-2y）(y-3x)=3xy-9x^2-2y^2+6xy=-9x^2-2y^2+9xy