ANSWER
[tex]y = 3x - 3[/tex]
EXPLANATION
Let
[tex]y = mx + c[/tex]
be the equation.
We can choose any two ordered pairs to determine the equation of the relation.
[tex](6,15) \: and \: (8,21)[/tex]
We find m using the formula;
[tex]m = \frac{y_2-y_1}{x_2-x_1} [/tex]
[tex]m = \frac{21 - 15}{8 - 6} = \frac{6}{2} = 3[/tex]
The equation becomes
[tex]y = 3x + c[/tex]
When x=6, y=15.
This implies that,
[tex]15 = 3(6) + c[/tex]
[tex]15= 18 + c[/tex]
[tex]15 - 18= c[/tex]
[tex]c = -3[/tex]
The equation of the relation is therefore,
[tex]y = 3x -3[/tex]
