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
:
![y - (1)/(5) xy = (1)/(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/rba4tv2asi4426uf92iyyzd2firlgeghy2.png)
Factorise y out on the left hand side:
![y(1 - (1)/(5) x) = (1)/(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/gn9w5zlnezggsd3flfqfci8ja526nqo32r.png)
Make y the subject of formula:
![y = (1)/(2) / (1 - (1)/(5) x) \\ y = (1)/(2) / ( (5)/(5) - (x)/(5) ) \\ y = (1)/(2) / (5 - x)/(5) \\ y = (1)/(2) * (5)/(5 - x) \\ y = (5)/(2(5 - x))](https://img.qammunity.org/2021/formulas/mathematics/high-school/vitremvka4lxarg72f2iwbk7vtto8e5ru2.png)
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.
![y = (2.5)/(5 - x)](https://img.qammunity.org/2021/formulas/mathematics/high-school/4mfavsjy4ty6p3otsx9i8zehtsunbk40bt.png)
Thus, a= 2.5 and b= 5.