Because C is a denominator first multiply by C
CF + 3 = Ce
Collect the like terms (the ones that contain C)
CF - Ce = -3
Factorise
C(F - e) = -3
C = -3/(F - e)
A better answer is C = 3/(e - F)
Subtract F from both sides
3/C = e - F
Divide by 3
1/C = (e - F)/3
Find reciprocal of both sides
C = 3/(e - F)
