5x-5/7x-7* 6x-6/14x-14

Using Order of Operations (PEMDAS - Parenthesis, Exponents, Multiplication and Division, Addition and Subtraction):

5x - 5/7x - 7 * 6x - 6/14x - 14

5x - 5/7x - 42x - 6/14x - 14

At this point I converted 5/1x to 35/7x for easy subtraction:

30/7x - 42x - 6/14x - 14

Another conversion: 42/1x to 294/7x ($${\mathtt{42}}{\mathtt{\,\times\,}}{\mathtt{7}} = {\mathtt{294}}$$):

264/7x - 6/14x - 14

A third conversion: 264/7x to 528/14x

522/14x - 14

261/7x - 14