说明多项式说明（a-2)(a²+2a+4)-[3a(a+1)²-2a(a-1)²-（3a+

说明多项式说明（a-2)(a²+2a+4)-[3a(a+1)²-2a(a-1)²-（3a+ 5a²-3a²+3(a²-b²)-2(5a²+2b²)怎么合 设复数z=(a²-1)+(a²-3a+2)i,若z² 1-a-b/a+2a/a²-b²/a²+4ab+4b² 求化简 , 若2a²+3a+b=4,求｛（a+b)(a-b)+(a-b)²+4a²（a+1）｝/a的值 2（a²+b²)(a+b)²-(a²-b²)² 已知A=4a²-3a,B=2a²+a-1,求2A-3B. 2（a²b+3ab²）-3(a²b-1)-2a²b-2 先化简,再求值:(a-1)/(a+2)*(a²-4)/(a²-2a+1)÷1/(a²-1) 1、（ ）-3a²+5a-7=-2a²+2a+1 通分：a-1/(a+1)²-4,1-a/2-4a+2a² 2a²b-[3ab²-4(ab²-3/4a²b)-1/2ab²,其中a