(1/2a+1/3b)(1/3b-1/2a)-(1/3b-1/2a)^2+(-1/3b-1/2a)^2 其中a=1/2 b=-1/3先化简后求值

(1/2a+1/3b)(1/3b-1/2a)-(1/3b-1/2a)^2+(-1/3b-1/2a)^2 其中a=1/2 b=-1/3先化简后求值
(1/2a+1/3b)(1/3b-1/2a)-(1/3b-1/2a)^2+(-1/3b-1/2a)^2 其中a=1/2 b=-1/3
先化简后求值

(1/2a+1/3b)(1/3b-1/2a)-(1/3b-1/2a)^2+(-1/3b-1/2a)^2 其中a=1/2 b=-1/3先化简后求值
(1/2a+1/3b)(1/3b-1/2a)-(1/3b-1/2a)^2+(-1/3b-1/2a)^2
=(1/3b+1/2a)(1/3b-1/2a)+(1/3b+1/2a)^2 -(1/3b-1/2a)^2
=(1/3b+1/2a)(1/3b-1/2a)+(1/3b+1/2a +1/3b-1/2a)(1/3b+1/2a -1/3b+1/2a)
=(1/3b)²-(1/2a)²+(2/3ab)
化简完毕 将a=1/2 b=-1/3 代入得
=[1/3(-1/3)]²-[1/2(1/2)]+2/3(1/2)(-1/3)
=1-1+4
=4