化简ab-3a+4b+8

化简：a-(3ab+b)+(3a-4b-ab) 化简:5(3a^2b-ab^2)-4(-ab^2+3a^2b) 化简 2a-(5ab+b)+(3a-4b-ab) a^2b-ab+2ab^2-5a^b-4ab+3ab^2化简快 (2a-5b+3ab)+(3a-b)-(8a-9b+ab),其中a-b=4,ab=3 化简 3a²-[2ab-2(ab-3/2a²b)+ab]+4ab² (3a+b)(3a-b) (-1/2a-b) (3y+2x)^2 (3ab+2b)^2 -8a^4b^/6ab^2 (3 已知A=3A^2B+3AB^2+B^4,B=-8AB^2+2A^2B+C^4,求A-2B 规定一种新运算:a*b=a+b,a@b=a-b,其中a、b为有理数,化简a^2b*3ab+5a^2b@4ab,并求出当a ^3ab^2-5ab^3-3ab^2+5b^3a-8a^3b^2+8a^2b^3化简 化简3a^2b-ab^2+2a^2b^2-3a^2b-3ab^2+4ab^2 合并同类项： -5a^b+6ab^-4ab-2a^b+4ab+3