Use the table given alongside to draw the graph of a straight line. Find, graphically, the values of a and b.

x	1	2	3	a
y	-2	b	4	-5

Steps of construction :

1. Plot the points (1, -2) and (3, 4) on graph paper.

2. Connect the points through a straight line.

3. Take a point C (x = 2) and draw a line parallel to y-axis touching the graph at point B.

4. From point B draw a line parallel to x-axis and touching y-axis at point A (y = 1).

From graph,

B = (2, 1)

Comparing it with (2, b) we get :

b = 1.

Also, the graph touches y-axis at (0, -5).

Comparing it with (a, -5) we get :

a = 0.

Hence, a = 0 and b = 1.