Question

Draw a graph of the equation 5x - 3y = 1. From the graph find the value of:
(i) x, when y = 8
(ii) y, when x = 2

Answer 1

We have
5x - 3y = 1
⇒ -3y = 1 - 5x
⇒ 3y = 5x - 1

⇒ y = `(5x - 1)/(3)`
When x = -2

⇒ y = `-(11)/(3)` = -3.66
When x = 0

⇒ y = `-(1)/(3)` = -0.33
When x = 2

⇒y = `(9)/(3)` = 3

x	-2	-1	0	1	2
y	-3.66	-2	-0.33	1.33	3

Thus ordered pairs of 5x - 3y = 1 are {(-2, -3.66), (-1, -2), (0, -0.33), (1, 1.33), (2, 3)}. Hence graph is a below.

(i) x, when y = 8
From graph we find that x = 5, when y = 8
(ii) y, when x = 2
From graph we find that y = 3, when x = 2.