The value of #y# varies directly with #x#, and #y=1# when #x=2#. What is #y# when #x=4#?

2 Answers
Apr 15, 2018

2

Explanation:

Here, #y prop x#
#rArr y = kx# where k is constant.
#rArr 1 = k.2# [put y =1,x=2]
#rArr k = 1/2#

Again, y = kx
#rArr y = 1/2×4#[put x = 4]
#rArr Y = 2#

Apr 15, 2018

#y=2#

Explanation:

#"the initial statement is "ypropx#

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

#rArry=kx#

#"to find k use the given condition"#

#y=1" when "x=2#

#y=kxrArrk=y/x=1/2#

#"equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(y=1/2x)color(white)(2/2)|)))#

#"when "x=4" then"#

#y=1/2xx4=2#