A premium ticket \( \mathrm{f}: \) a football match was one and a half times the price of a standard ticket. If the total cost for 4 standard and 2 premium tickets was €322, write an equation to show this information. Solve the equation to find the cost of a standard ticket.

d. \( 2 x^{2}+27=-21 x \)

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

b. \( x^{2}+2 x=15 \)

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

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.