If y varies directly as x and #y=28# and #x=18#, how do you find y when #x = 9#?

1 Answer
Jim G.
May 25, 2018

#y=14#

Explanation:

#"the initial statement is "ypropx#

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

#y=kx#

#"to find k use the given condition"#

#y=28" when "x=18#

#y=kxrArrk=y/x=28/18=14/9#

#"equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(y=14/9x)color(white)(2/2)|)))#

#"when "x=9" then"#

#y=14/cancel(9)xxcancel(9)=14#

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