Example y = 2x 1 is a linear equation The graph of y = 2x1 is a straight line When x increases, y increases twice as fast, so we need 2x; NCERT Exemplar Class 9 Maths Chapter 4 Exercise 44 Question 1 Show that the points A (1, 2), B (1, 16) and C (0, – 7) lie on the graph of the linear equation y = 9x – 7 Solution Firstly, to draw the graph of equation y = 9x – 7, we need atleast two solutions When x = 2, then y = 9 (2) – 7 = 18 – 7 = 11Linear functions commonly arise from practical problems involving variables , with a linear relationship, that is, obeying a linear equation =If , one can solve this equation for y, obtaining = = , where we denote = and =That is, one may consider y as a dependent variable (output) obtained from the independent variable (input) x via a linear function = =
Graphing Linear Inequalities