(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
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![(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](/uploads/image/z/2639518-70-8.jpg?t=%281%2F2a%2B1%2F3b%29%281%2F3b-1%2F2a%29-%281%2F3b-1%2F2a%29%5E2%2B%28-1%2F3b-1%2F2a%29%5E2+%E5%85%B6%E4%B8%ADa%3D1%2F2+b%3D-1%2F3%E5%85%88%E5%8C%96%E7%AE%80%E5%90%8E%E6%B1%82%E5%80%BC)
(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