The sum of the present ages of a father and his son is 80 years. When the

father's age was equal to the present age of the son, the sum of their ages

would be 40 years. Find their present ages.

Father=60

Son=20

Step-by-step explanation:

Let the father's age be x

Let the son age be y

Present age of them

X+y=80 ... (1)

Since the father's age equals to the present age of the son

Y+y=40

2y=40 ... (2)

Make y the subject of formula by dividing both sides by 2

Y=20

Substitute the value for x into (1)

20+x=80

Substrate 20 from both sides

X=60

Therefore the father's age is 60 and the son's age is 20