Answer:
a= 2.5, b= 5
Explanation:
Since the graph is obtained by plotting y against xy, Y= y and X= xy. (Linear law: Y=mX +c)
Given that the line intersects the vertical axis at (0, ½), the y-intercept is ½.
Equation of the line: Y= mX +½
Given that the gradient is ⅕, m= ⅕.
Y= ⅕X +½
Substitute Y= y and X=xy:
y= ⅕xy +½
Rewrite the equation such that it is in the form of
:

Factorise y out on the left hand side:

Make y the subject of formula:

Do not expand at this step as the coefficient of x in the equation is 1. Instead, divide both the numerator and denominator by 2.

Thus, a= 2.5 and b= 5.