已知丨a+2丨+(b+1)²+(c-1/3)²=0,求代数式5abc-{2a²b-[3abc-(4ab²-a²b)]}谢了,要讲解.
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![已知丨a+2丨+(b+1)²+(c-1/3)²=0,求代数式5abc-{2a²b-[3abc-(4ab²-a²b)]}谢了,要讲解.](/uploads/image/z/7094244-12-4.jpg?t=%E5%B7%B2%E7%9F%A5%E4%B8%A8a%2B2%E4%B8%A8%2B%EF%BC%88b%2B1%EF%BC%89%26%23178%3B%2B%EF%BC%88c-1%2F3%EF%BC%89%26%23178%3B%3D0%2C%E6%B1%82%E4%BB%A3%E6%95%B0%E5%BC%8F5abc-%EF%BD%9B2a%26%23178%3Bb-%5B3abc-%284ab%26%23178%3B-a%26%23178%3Bb%29%5D%EF%BD%9D%E8%B0%A2%E4%BA%86%2C%E8%A6%81%E8%AE%B2%E8%A7%A3.)
已知丨a+2丨+(b+1)²+(c-1/3)²=0,求代数式5abc-{2a²b-[3abc-(4ab²-a²b)]}谢了,要讲解.
已知丨a+2丨+(b+1)²+(c-1/3)²=0,求代数式5abc-{2a²b-[3abc-(4ab²-a²b)]}
谢了,要讲解.
已知丨a+2丨+(b+1)²+(c-1/3)²=0,求代数式5abc-{2a²b-[3abc-(4ab²-a²b)]}谢了,要讲解.
因为:丨a+2丨+(b+1)²+(c-1/3)²=0
所以:a+2=0 b+1=0 c-1/3=0
所以:a=-2 b=-1 c=1/3
所以:5abc-{2a²b-[3abc-(4ab²-a²b)]}=5abc--2a^2b+3abc-4ab^2+a^2b
=8abc-a^2b-6ab^2=8*(-2)*(-1)*1/3-4*(-1)-6*(-2)*1
=64/3
a=-2 b=-1 c=1/3
abc=2/3
5abc-{2a²b-[3abc-(4ab²-a²b)]}
=10/3-{-8-[2-(-8+4)]}
=10/3+14
=52/3
由于绝对值和平方都是非负的,所以a+2=0且b+1=0 c-1/3=0
由此得到 a=-2,b=-1,c=1/3 代入原式,
得到5abc-{2a²b-[3abc-(4ab²-a²b)]}=17+1/3