a=1/20x+20.b=1/20x+19,c=1/20x+21求代数式a²+b²+c²-ab-bc-ac的值?
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![a=1/20x+20.b=1/20x+19,c=1/20x+21求代数式a²+b²+c²-ab-bc-ac的值?](/uploads/image/z/4085337-57-7.jpg?t=a%3D1%2F20x%2B20.b%3D1%2F20x%2B19%2Cc%3D1%2F20x%2B21%E6%B1%82%E4%BB%A3%E6%95%B0%E5%BC%8Fa%26%23178%3B%2Bb%26%23178%3B%2Bc%26%23178%3B-ab-bc-ac%E7%9A%84%E5%80%BC%3F)
a=1/20x+20.b=1/20x+19,c=1/20x+21求代数式a²+b²+c²-ab-bc-ac的值?
a=1/20x+20.b=1/20x+19,c=1/20x+21求代数式a²+b²+c²-ab-bc-ac的值?
a=1/20x+20.b=1/20x+19,c=1/20x+21求代数式a²+b²+c²-ab-bc-ac的值?
原式=1/2(2a²+2b²+2c²-2ab-2bc-2ac)
=1/2【(a-b)²+(a-c)²+(b-c)²】
=1/2(1-1-2)
=-1