Example 2 - Romila went to a stationery shop and purchased

Example 2 - Chapter 3 Class 10 Pair of Linear Equations in Two Variables - Part 2
Example 2 - Chapter 3 Class 10 Pair of Linear Equations in Two Variables - Part 3
Example 2 - Chapter 3 Class 10 Pair of Linear Equations in Two Variables - Part 4
Example 2 - Chapter 3 Class 10 Pair of Linear Equations in Two Variables - Part 5

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Question 2 Romila went to a stationery shop and purchased 2 pencils & 3 erasers for Rs 9. Her friend Sonali saw the new variety of pencils and erasers with Romila, and she also bought 4 pencils and 6 erasers of the same kind for Rs 18. Represent this situation algebraically and graphically. Let the Cost of Pencil be Rs x & Let the Cost of Eraser be Rs y Given that Romila purchased 2 pencils & 3 erasers for Rs 9 2 × (Cost of pencil) + 3 × (Cost of eraser) = 9 2x + 3y = 9 Also, Her friend Sonali saw the new variety of pencils and erasers with Romila, and she also bought 4 pencils and 6 erasers of the same kind for Rs 18 Sonali purchased 4 pencils and 6 erasers for Rs 18 4 × (Cost of pencil) + 6 × (Cost of eraser) = 18 4x + 6y = 18 Now, plotting equations 2x + 3y = 9 ...(1) 4x + 6y = 18 …(2) For Equation (1) 2x + 3y = 9 Let x = 0 2(0) + 3y = 9 3y = 9 y = 9/3 y = 3 So, x = 0, y = 3 is a solution i.e. (0, 3) is a solution Let y = 0 2x + 3(0) = 9 2x = 9 x = 9/2 x = 4.5 So, x = 4.5, y = 0 is a solution i.e. (4.5, 0) is a solution For Equation (2) 4x + 6y = 18 Let x = 0 4(0) + 6y = 18 6y = 18 y = 18/6 y = 3 So, x = 0, y = 3 is a solution i.e. (0, 3) is a solution Let y = 0 4x + 6(0) = 18 4x = 18 x = 18/4 x = 4.5 So, x = 4.5, y = 0 is a solution i.e. (4.5, 0) is a solution We will plot both equations on the graph

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.