Explanation
Step 1
as the cost per unit is 7.5 , we can set a function
[tex]\begin{gathered} total\text{ cost=}7.5x \\ where\text{ is is the number of shirts, } \end{gathered}[/tex]
so
a)for x=1
[tex]\begin{gathered} total\text{ cost=}7.5x \\ tota\text{l cost=}7.5*1=7.5 \end{gathered}[/tex]
b))for x=2
[tex]\begin{gathered} total\text{ cost=}7.5x \\ tota\text{l cost=}7.5*2=15 \end{gathered}[/tex]
c)forx= 3
[tex]\begin{gathered} total\text{ cost=}7.5x \\ tota\text{l cost=}7.5*3=22.5 \end{gathered}[/tex]
d)for x=4
[tex]\begin{gathered} total\text{ cost=}7.5x \\ tota\text{l cost=}7.5*4=305 \end{gathered}[/tex]
so, the answer is
