Let the age of son be x and that of his father be y.
According to the question, we have
y=x+30 [∵ Father is 30 years older then his son ]
⇒y−x=30.....(i)
and x+y=56 ....(ii) [Sum of their ages is 56]
Adding equation(i) and (ii), we have
⇒y−x+x+y=30+56
⇒2y=86
⇒y=43
Substitute y=43 in equation (i), we get
y=x+30
43−30=x
∴x=13