Question

Draw the graph of the lines represented by the equations x + y = 4 and 2x - y = 2 on the same graph. Find the coordinates of the point where they intersect

Answer 1

For,
x + y = 4
y = 4 - x
When x = 3, y = 4 - 3 = 1
When x = 0, y = 4 - 0 = 4
When x = -1, y = 4 - (-1) = 5

x	3	0	-1
y	1	4	5

For,
2x - y = 2
y = 2x - 2
When x = 3, y = 2(3) - 2 = 4
When x = 0, y = 2(0) -2 = -2
When x = -1, y = 2(-1) -2 = -4

x	3	0	-1
y	4	-2	-4

Plotting thses co-ordinates on the graph, we get the lines shown as: (2, 2)

The point of intersection is (2, 2).