3c+2f=22

I have to find a number for both c and f. What would be some answers/examples?

It is impossible to solve for 2 unknown variables in an equation. In order to solve this, you must think mentally.

What two numbers can you add to make 22?

A good example is 15 and 8.

Can 15 and 8 be divided into smaller numbers?

Yes.

15/3 = 5

8/2 = 4

^

Notice how I'm dividing by the coefficient? * 3*c and * 2*f

So C can be 5 and F can be 4.

3 (5) + 2 (4) = 22

15 + 8 = 22

22 = 22

3C+2F=22

3C + 2F-2F = 22-2F

3C = 22 - 2F

3C:3 = 22:3 - 2F:3

C = 22/3-2F/3

3C+2F=22

3C-3C + 2F = 22 - 3C

2F = 22 - 3C

2F:2 = 22:2 - 3C:2

F = 11-3C/2