[tex]\begin{gathered} S\text{ince x represents the number of T-shirts Lee bought, } \\ \text{The total bill should be number of T-shirts multiplied by the cost for one} \\ T-\text{shirt } \end{gathered}[/tex][tex]\begin{gathered} So,\text{ \$15.50 }\times x\text{ = \$124} \\ \text{Answer is 15.50 }x\text{ = 124} \end{gathered}[/tex]