I know 7/9 - x = 1/36 is 3/4 but how do I show the work

Answer 1

7/9 - x = 1/36

find LCD, LCD = 36

28/36 - x = 1/36
28/36 - 1/36 = x
27/36 = x

reduce fraction
3/4 = x

Answer 2

7/9 - x = 1/36
7/9 - 1/36 = x
28/36 - 1/36 = x
27/36 = x

Divide 27 and 36 by 9.

27/36 = 3/4