Last updated at Dec. 18, 2020 by Teachoo

Transcript

Example 4 Check graphically, whether the pair of equations x + 3y = 6 and 2x – 3y= 12 is consistent. If so, solve them graphically. Let equations be x + 3y = 6 2x – 3y = 12 Let’s draw their graphs For Equation (1) x + 3y = 6 Putting x = 0 0 + 3y = 6 3y = 6 y = 6/3 y = 2 So, x = 0, y = 2 is a solution i.e. (0, 2) is a solution Putting y = 0 x + 3(0) = 6 x + 0 = 6 x = 6 So, x = 6, y = 0 is a solution i.e. (6, 0) is a solution For Equation (2) 2x − 3y = 12 Putting x = 0 2(0) − 3y = 12 0 − 3y = 12 −3y = 12 y = 12/(−3) y = −4 So, x = 0, y = −4 is a solution i.e. (0, −4) is a solution Putting y = 0 2x − 3(0) = 12 2x = 12 x = 12/2 x = 6 So, x = 6, y = 0 is a solution i.e. (6, 0) is a solution We will plot both equations on the graph Since the lines intersect, the given equations are consistent And solution is (6, 0)

About the Author

Davneet Singh

Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.