Question

The cost of ball pen is Rs. 5 less than half of the cost of fountain pen. Write this statement as a linear equation in two variables.

Answer 1

The required linear equation in two variables is 2x – y + 10 = 0

Step-by-step explanation:

Let the cost of a fountain pen be  'y' and cost of a ball pen be 'x'.

Given :  

Cost of a ball pen = ₹ 5 less than the  

Cost of fountain pen  

According to the statement , we have

x = ½ × y - 5

x = y/2 − 5

x = (y - 2 × 5)/2

x = (y - 10)/2

2x = y – 10

2x – y + 10 = 0

Hence, the required linear equation in two variables is 2x – y + 10 = 0

Answer 2

Given

• Cost of a ball pen = ₹ 5 less than the  

Cost of fountain pen  

Let the cost of a fountain pen be  'y' and cost of a ball pen be 'x'.

According to the question

x = ½ × y - 5

x = y/2 − 5

x = (y - 2 × 5)/2

x = (y - 10)/2

2x = y – 10

2x – y + 10 = 0

Therefore, the required linear equation in two variables is 2x – y + 10 = 0