Your system of equation is m + f = 65, (1) f =+ 5. (2) To rid of the denominator, multiply (2) by 5 (both sides). Then you get your system in the form m + f = 65, (1') 5f = m + 25. (2') Can you solve it on your own? Use the substitution method. Answer. 50 male, 15 females.