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四个数,a,x,b,2x成等差数列,求a/b的值

题目详情
四个数,a,x,b,2x成等差数列,求a/b的值
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答案和解析
因为a,x,b,2x成等差数列,设公差为d,则x = a + d ,2x = b + d,
又,2x = a + b,推出b + d = a + b,即a = d,
而x = a + d,推出x = 2d,
又2b = x + 2x = 3x =6d,推出b = 3d,
所以a/b的值等于d/3d = 1/3