Question

After three years, a man’s age will be five times his son’s age. If the man's current age is represented by 'x' and his son's age by 'y', which among the following options is a linear equation in two variables representing this statement?

• A. $5x-y=12$
• B. $x+5y=12$
• C. $x-5y=12$
• D. $5x-y=12$

Answer 1

The correct option is C $x-5y=12$

After three years,
Man's age = $(x+3)$ years
Son's age = $(y+3)$ years

According to the question, we have
$x+3=5(y+3)$
$\Rightarrow x+3=5y+15$
$\Rightarrow x-5y=12$
$\therefore x-5y=12$ is the linear equation in two variables.