A man is 20 years older than his son.if the sum of their ages is 50 years, find their ages ?

2 answers

you take the difference of their ages, 20, away from the total of their ages, 50, (which leaves 30) and then divide the rest of the years between them, that's 15 each.
M = S + 20

M + S = 50

Substitute S+20 for M in the second equation and solve for M. Insert that value into the first equation to solve for S. Check by putting both values into the second equation.