Check sibling questions

Example 7 - Solve by substitution 7x - 15y = 2 & x + 2y = 3

Example 7 - Chapter 3 Class 10 Pair of Linear Equations in Two Variables - Part 2
Example 7 - Chapter 3 Class 10 Pair of Linear Equations in Two Variables - Part 3 Example 7 - Chapter 3 Class 10 Pair of Linear Equations in Two Variables - Part 4

This video is only available for Teachoo black users


Transcript

Example 7 Solve the following pair of equations by substitution method: 7x – 15y = 2 x + 2y = 3 7x – 15y = 2 x + 2y = 3 From (1) 7x – 15y = 2 7x = 2 + 15y x = (𝟐 + 𝟏𝟓𝒚)/𝟕 Substituting the value of x in (2) x + 2y = 3 (2 + 15𝑦)/7 + 2𝑦=3 Multiplying both sides by 7 7 × ((2 + 15𝑦)/7) +7×2𝑦=7×3 (2 + 15y) + 14y = 21 15y + 14y = 21 – 2 29y = 21 – 2 29y = 19 y = 𝟏𝟗/𝟐𝟗 Putting value of y in equation (2) x + 2y = 3 x + 2(19/29) = 3 x + 38/29 = 3 x = 3 – 38/29 x = (3(29) − 38)/29 x = (97 − 38)/29 x = 𝟒𝟗/𝟐𝟗 Hence, x = 49/29,y=19/29 is the solution of the equation

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.