If y varies inversely as x and y = 12 when x = 3, how do you find x when y = 18?

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Answer 1 · 2016-10-01T08:22:42

#x=2#

As #y# varies inversely as #x#, #yprop1/x# or #y=kxx1/x#

i.e. #x xxy=k#

Hence as when x=3#, #y=12#, we have

#k=3xx12=36#

and therefore when #y=18#

we have #x xx18=36#

or #x=36/18=2#