If Df = 9x -39, find EF

To simplify a fraction, you need to find a common factor between the numerator and the denomenator, and divid both parts by that until you cannot anymore.

exg 84/54

both 84 and 54 are divisible by 2 ->
84 divided by 2 = 42
54 divided by 2 = 27

now, both 42 and 27 are divisible by 3 ->
42 diveded by 3 = 14
27 divisible by 3 = 9

so we are currently at 14/9. they have no common factor, so we cannot divide them further.

to completely simplify this, we will turn 14/9 into 1 and 5/9 (this is because 9 fits into 14 once, and the remainder is 5).