<PRE><B>Question 275518</B>
your problem states:


When x = 2 and y = 3, z = 42. Write the function that models each of the following relationships.


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1. z varies inversely with x and directly with y. (1 point)


formula would be z = ky/x


substitute:


x = 2
y = 3
z = 42


formula becomes:


42 = k*3/2 **************************************************


solve for k to get:


k = 2*42/3 = 28


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2. z varies jointly with x and y (1 point)


formula is z = kxy


substitute:


x = 2
y = 3
z = 42


formula becomes:


42 = k*2*3 *******************************************************


solve for k to get:


k = 42/6 = 7


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3. z varies directly with x and inversely with the square of y (1 point) 


formula is:


z = kx/y^2


substitute:


x = 2
y = 3
z = 42


formula becomes:


42 = k*2/(3^2) = k*2/9 ************************************************


solve for k to get:


k = 42*9/2 = 189


they did not ask you to solve the equations.


they only asked you to write the functions.


functions with the ****************************************** next to them should be your answers.


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