(a-b)^4÷(b-a)^3

计算：3a+4b/a-b+3b/b-a-4a/a-b 3a/a-4b +a+b/4b-a -7b/a-4b 1.（a-b)^2（b-a)^3(a-b)^-4 (3a-6b)/(a+b) - (5a-6b)/(a-b) - (4a-5b)/(a+b) - (7a-8b)/(a-b (3a-6b/a+b）-(5a-6b/a-b)-(4a-5b/a+b)-(7a-8b/b-a) [8(a+b)^6+4(a+b)^4+(-a-b)^3]÷[2(a+b)＾3]. 计算：[（2a+b）（2a-b）-4a（a-b）+3b2]÷2b． 先化简再求值[(3a+2b)(3a-2b)-(a+2b)(a-2b)]÷(4a),其中|a-2|+(b+3)^2=0 先化简,再求值:[(3a+2b)(3a-2b)-(a+2b)(5a-2b)]÷4a,其中a=2,b=-3 化简：1÷(3b/3a÷4b/9a×3a/2b) [（a+2b)(a-2b)-(2a-b)²+(3a-b)(3a-5b)]÷2a 计算a^-2b^-3*(-3a^-1b^2)÷6a^-4b^-2