f+1/3= 4/5

2. Next we need to make f stand alone

f+1/3-1/3=4/5-1/3

Subracting 1/3 will undo the addition, and to make it stay the same value do the same to the other side- subtract 1/3

3. make the denominators the same you will need to change both 1/3 and 4/5 denominators to 15.

1/3×5/5= 5/15

4/5×3/3=12/15

f=12/15-5/15

Now subtract 5/15 from 12/15. I won’t give you the answer but after reading this it should be extremely easy to figure out.

4/5 -1/3=f

then find a common number for 3 and 5 which will be 15 , because 3 x 5 = 15 and put it as a common denominator and then multiply the numerator by the number they have missing:

(4 x 3)/15 – (1×5)/15 = f

12/15 – 5/15 = f

now you can subtract the fractions and make it one

12 – 5 = 7 so the answer will be f = 7/15

You can verify your answer by substituting your f with 7/15,

1/3 + 7/15 = 12/15 = 4/5

Hope this helps.

4/5(3/3) = 1/3(5/5) + f

12/15 = 5/15 + f

7/15 = f

therefore:

4/5 – 1/3 = f

convert to common denominator

12/15 – 5/15 = f

so:

7/15 = f

4/5 – 1/3

12/15 – 5/15 = 7/15

7/15 – f

answer f=7/15