Question

Write the linear equations in two variables for the given information :
Five years from present, the age of Sachin will be three times that of his son. Five years ago, Sachin’s age was seven times that of his son.

Answer 1

Let present ages of Sachin & his son are x years and y years.

Five years from present,

age of Sachin = (x + 5) years & his son’s age = (y + 5) years

according to question,
(x + 5) = 3(y + 5)

Þ x + 5 = 3y + 15

Þ x – 3y = 10 ……(i)

and 5 years ago age of both were
(x – 5) years and (y – 5) years respectively

according to question,
(x – 5) = 7(y – 5)

Þ x – 5 = 7y – 35

Þ x – 7y = –30 .…(ii)