Question

3c+2f=22
I have to find a number for both c and f. What would be some answers/examples?

Answer 1

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

Answer 2

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