# If #y# varies inversely as the square of #x# and #y=4# when #x=5#, what is #y# when #x# is #2#?

##### 1 Answer

Jun 6, 2017

#### Answer:

#### Explanation:

#"the initial statement is " yprop1/x^2#

#"to convert to an equation, multiply by k, the constant"#

#"of variation"#

#rArry=kxx1/x^2=k/x^2#

#"to find k use the given condition"#

#y=4" when " x=5#

#y=k/x^2rArrk=x^2y=5^2xx4=100#

#"the equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(y=100/(x^2))color(white)(2/2)|)))#

#"when "x=2#

#rArry=100/(2^2)=100/4=25#