(13x/7)-x+(x/4)-(3/14)

The denominators are 7, 4, and 14   --->   a common denominator is  7 x 4  =  28.

Write each term with a denominator of 28:

(13x/7)·(4/4) - x·(28/28) + (x/4)·(7/7) - (3/14)·(2/2)

52x/28 - 28x/28 + 7x/28 - 6/28

(52x - 28x +7x -6)/28

Now finish the simplifications.

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