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Hello :) how to do this question?:)

Hello :) how to do this question?:)-example-1
User Mehdok
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1 Answer

4 votes

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 = (a)/(b - x):


y - (1)/(5) xy = (1)/(2)

Factorise y out on the left hand side:


y(1 - (1)/(5) x) = (1)/(2)

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))

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)

Thus, a= 2.5 and b= 5.

User Marcerickson
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