Y varies inversely with twice the value of x. When y = 8, x = 2. How do you find y when x = 8?

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Answer 1 · 2016-03-28T19:55:17

#y=2" at "x=8#

#y= kxx1/(2x)#

#"so "2xy=k#

Given that when #y=8", "x=2# so we have:

#2(2)(8)=k#

#=> k=32#

So our equation becomes:

#y=32/(2x)#

This is the same as:

#y= 32/2 xx1/ x#

so #y= 16/x#
'~~~~~~~~~~~~~~~~~~~~~~~~~~~
So when #x=8#

#color(brown)(y=16/x)color(blue)(" " ->" " y=16/8 = 2)#