THU GỌN BIỂU THỨC :|x-2/5|+|x+1/3|-2(x-1/2)

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1. Đáp án:

   Nếu `x>=2/5`

   `=>|x-2/5|=x-2/5,|x+1/3|=x+1/3`

   `=>|x-2/5|+|x+1/3|-2(x-1/2)`

   `=x-2/5+x+1/3-2x+1`

   `=3/5+1/3=14/15`

   Nếu `x<=-1/3`

   `=>|x-2/5|=2/5-x,|x+1/3|=-x-1/3`

   `=>|x-2/5|+|x+1/3|-2(x-1/2)`

   `=2/5-x-x-1/3-2x+1`

   `=-4x+2/5+2/3`

   `=-4x+16/15.`

   Nếu `-1/3<=x<=2/5`

   `=>|x-2/5|=2/5-x,|x+1/3|=x+1/3`

   `=>|x-2/5|+|x+1/3|-2(x-1/2)`

   `=2/5-x+x+1/3-2(x-1/2)`

   `=2/5+1/3-2x+1`

   `=-2x+2/5+4/3`

   `=-2x+26/15.`

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