If Y varies inversely as twice x. When x = 3, y = 6 what is the value of y when x = 9?

2 Answers
Jan 2, 2018

Answer:

#y=2#

Explanation:

If #y# is inversely proportional to #2x#, therefore #2x*y=k# for some constant #k#

When, #x=3#, #y=6#, #:. k=36#

#:. 2xy=36#

When #x=9#, #y=36/(2x)=36/18=2#

#:. y=2# when #x=9#

Jan 2, 2018

Answer:

#y=2#

Explanation:

#"the initial statement is "yprop1/(2x)#

#"to convert to an equation multiply by k the "#
#"constant of variation"#

#rArry=kxx1/(2x)=k/(2x)#

#"to find k use the given condition"#

#"when "x=3, y=6#

#y=k/(2x)rArrk=2xy=2xx3xx6=36#

#"equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(y=36/(2x)=18/x)color(white)(2/2)|)))#

#"when "x=9#

#rArry=18/9=2#