Answer :
In order to write the expressions for number 11 we consider the cost for each of the items
then,
a)
each soccerball costs $14 and each baseball costs $9
then
[tex]\begin{gathered} C=14\cdot x+2\cdot9 \\ C=14x+18 \end{gathered}[/tex]b)
each pair of sweat socks costs $7 and each baseball costs $9
then
[tex]\begin{gathered} C=2\cdot(7\cdot x+9) \\ C=14x+18 \end{gathered}[/tex]