Question

If y varies inversely as x and y = 27 when x = 2, find x when y = 9. *

Answer 1

Given that y varies inversely as x then:
y=k/x
where
k is the constant of proportionality given by:
k=yk
but
y=27 when x=2
thus
k=27×2=54
hence the function will be:
y=54x
The value of x when y is 9 will be:
9=54x
thus
x=9/54
x=1/6