11) Sarah is planning a birthday party for her friends and family and wants to make sure that the number of total guests is neither too few nor too many. She has space to comfortably host between 15 and 30 total guests. Sarah has 4 family members that are already planning on coming and is trying to decide how many friends she can invite. If \( x \) represents the number of friends she can invite, write a compound inequality that describes the possible number of guests she can invite.

Write an equation that expresses the following relationship. \( p \) varies jointly. with \( d \) and the square root of \( u \) In your equation, use \( k \) as the constant of proportionality. \( \square=\square \quad \frac{\square}{\square} \)

a. \( x^{2}=49 \)

Write an equation that expresses the following relationship. \[ d \text { varies directly with } w \text { and inversely with the square root of } p \] In your equation, use \( k \) as the constant of proportionality.

Write an equation that expresses the following relationship. \( w \) varies directly with the cube of \( u \) and inversely with \( d \) In your equation, use \( k \) as the constant of proportionality,

A one-to-one function is given. Write an equation for the inverse function. \( s(x)=\frac{2}{x+4} \) \( s^{-1}(x)=\square \)