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.
The given equation is y = 9x – 7. To draw the graph of this equation, we need at least two points lying on the graph.
For x = 0, y = – 7, therefore, (0, – 7) lies on the graph.
For y = 0, , therefore, (0.8, 0) lies on the graph.
Now plot the points M(0, – 7) and N (0.8, 0) and join them to get the line and now extend this straight line to get more solutions.
Now, to check that the given points are lying on the graph either we can take x and y pt. and draw perpendicular to the x-axis and y-axis to check if they lie on the graph(here, all are lying(as shown)) or we can put the given points in the equations and see if they are satisfying the equation or not.
If the given point satisfies the equation that means points lie on the graph. Therefore we’ll put the value of x and find the value of y for every point using equation y = 9x – 7.
• For pt. A(1, 2), x = 1 and y = 2
∴ Putting x = 1 in y = 9x – 7, we get-
⇒ y = 9×1 – 7
⇒ y = 2, that means pt. A lies on the graph.
• For pt. B( – 1, – 16), x = – 1 and y = – 16
∴ Putting x = – 1 in y = 9x – 7, we get-
⇒ y = (9× – 1) – 7
⇒ y = – 16, that means pt. B also lies on the graph.
• For pt. C(0, – 7), x = 0 and y = – 7
∴ Putting x = 0 in y = 9x – 7, we get-
⇒ y = (9×0) – 7
⇒ y = – 7, that means pt. C also lies on the graph.
Conclusion: Point A, B, C lies on the graph of equation y = 9x – 7