Class 10 Maths Chapter 3 Exercise 3.2 Question 1 (iii, iv) | Substitution Method | NCERT Solution

In this video, we have solved Exercise 3.2 Question 1 (Parts iii and iv) of Chapter 3 (Pair of Linear Equations in Two Variables) for CBSE and State Board Class 10 Maths in Hindi. Topic: Substitution Method (प्रतिस्थापन विधि) Question Covered: Solve the following pair of linear equations by the substitution method: (निम्न रैखिक समीकरण युग्म को प्रतिस्थापन विधि से हल कीजिए:) (iii) 3x - y = 3 , 9x - 3y = 9 (iv) 0.2x + 0.3y = 1.3 , 0.4x + 0.5y = 2.3 Topics and Steps Explained: Part (iii): • Given equations: 3x - y = 3 ---(1) 9x - 3y = 9 ---(2) • From equation (1): y = 3x - 3 ---(3) • Substituting value of y in equation (2): 9x - 3(3x - 3) = 9 9x - 9x + 9 = 9 9 = 9 • This statement is true for all values of x. • Therefore, the given pair of equations has infinitely many solutions (अपरिमित रूप से अनेक हल). Part (iv): • Given equations: 0.2x + 0.3y = 1.3 ---(1) 0.4x + 0.5y = 2.3 ---(2) • Multiplying both equations by 10 to remove decimals: 2x + 3y = 13 ---(3) 4x + 5y = 23 ---(4) • From equation (3): 2x = 13 - 3y x = (13 - 3y) / 2 ---(5) • Substituting value of x in equation (4): 4[(13 - 3y) / 2] + 5y = 23 2(13 - 3y) + 5y = 23 26 - 6y + 5y = 23 26 - y = 23 y = 26 - 23 y = 3 • Putting y = 3 in equation (5): x = (13 - 3*3) / 2 x = (13 - 9) / 2 x = 4 / 2 x = 2 • Final Answer: x = 2, y = 3 • Easy step-by-step handwriting method for CBSE and All State Boards ----------------------------------------------- Subscribe to The Maths Paper for complete Class 10 Maths NCERT solutions with easy handwriting step-by-step methods! Video pasand aaye toh Like aur apne dosto ke sath Share zaroor karein. ----------------------------------------------- #Class10Maths #LinearEquationsInTwoVariables #SubstitutionMethod #Class10MathsChapter3 #Exercise3_2 #NCERTClass10Maths #TheMathsPaper #CBSEClass10 #Class10BoardExam #PratisthapanVidhi