Question

Solve graphically : 5x – 3y ≤ 0

Answer 1

Consider the line whose equation is 5x – 3y = 0. The constant term is zero, therefore this line is passing through the origin.
∴ one point on the line is the origin O = (0, 0).
To find the other point, we can give any value of x and get the corresponding value of y.
Put x = 3, we get 15 – 3y =  0, i.e. y = 5
∴ A = (3, 5) is another point on the line. Draw the line OA.
To find the solution set, we cannot check O(0,0), as it is already on the line. We can check any other point which is not on the line.
Let us check the point (1, – 1).
When x = 1, y = – 1 then 5x –  3y = 5 + 3 = 8 which is neither less nor equal to zero.
∴ 5x – 3y `cancel<=` 0 in this case.
Hence (1, – 1) will not lie in the required region.
Therefore the required region is the upper side which is shaded in the graph.

This is the solution set of 5x – 3y ≤ 0.