# Whats the equation of variation where y varies jointly as x and z and inversely as the square of w and y=20 when x= -0.5, z =4, and w = 5?

##### 1 Answer

Nov 24, 2017

#### Explanation:

#"the initial statement is "yprop(xz)/w^2#

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

#"of variation"#

#rArry=kxx(xz)/w^2=(kxz)/w^2#

#"to find k use the given condition"#

#y=20" when "x=-0.5,z=4" and "w=5#

#y=(kxz)/w^2rArrk=(yxxw^2)/(xz)=(20xx5^2)/(-0.5xx4)=-250#

#"equation is " color(red)(bar(ul(|color(white)(2/2)color(black)(y=-(250xz)/w^2)color(white)(2/2)|)))#