

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class
Examples
Example 2
Example 3 Important
Example 4
Example 5 You are here
Example 6
Example 7 Important
Example 8 Important
Example 9
Example 10 Important
Question 1 Deleted for CBSE Board 2024 Exams
Question 2 Deleted for CBSE Board 2024 Exams
Question 3 Deleted for CBSE Board 2024 Exams
Question 4 Important Deleted for CBSE Board 2024 Exams
Question 5 Deleted for CBSE Board 2024 Exams
Question 6 Important Deleted for CBSE Board 2024 Exams
Question 7 Deleted for CBSE Board 2024 Exams
Question 8 Important Deleted for CBSE Board 2024 Exams
Question 9 Important Deleted for CBSE Board 2024 Exams
Last updated at May 29, 2023 by Teachoo
Example 5 Aftab tells his daughter, “Seven years ago, I was seven times as old as you were then. Also, three years from now, I shall be three times as old as you will be.” (Isn’t this interesting?) Solve by the method of substitution.. We formed the equations in Ex 3.1, 1 The equations are x – 7y = −42 ...(1) x – 3y = 6 …(2) From (1) x – 7y = −42 x = 7y – 42 Putting value of x in (2) x – 3y = 6 (7y – 42) – 3y = 6 7y − 3y = 6 + 42 4y = 48 y = 48/4 y = 12 Putting y = 12 in equation (1) x – 7y = −42 x – 7(12) = −42 x − 84 = −42 x = −42 + 84 x = 42 So, x = 42, y = 12 is the solution of the equations Hence, Aftab’s age = x = 42 years His daughter’s age = y = 12 years