If y = 7.2 when x = 10, what is the value of x when y = 20?

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Answer 1 · 2017-08-16T06:17:50

#y =3.6#

It seems that the question refers to an inverse variation?

The constant in an inverse variation is found from #color(red)(k = x xx y)#

From this we can find #x or y#, given the other one.

#x= k/y and y =k/x#

#k =7.2xx10=72#

therefore to find #y#:

#y= k/x= 72/20#

#y = 3.6#