Where:
c(m) is the cost of the holiday in m miles,
If m greater than 10 there is a discount of $1
So the cost will reduce by $1
[tex]c(m)=2+0.5m-1[/tex]Add the like terms
[tex]c(m)=1+0.5m\text{ , m>10}[/tex]This is the answer of (a)
The cost of the holiday was $7.5, which means
c(m) = 7.5
Let us substitute it in the equation above and find the value of m
[tex]7.5=1+0.5m[/tex]Subtract 1 from both sides
[tex]\begin{gathered} 7.5-1=1-1+0.5m \\ 6.5=0.5m \end{gathered}[/tex]Divide both sides by 0.5 to find m
[tex]\begin{gathered} \frac{6.5}{0.5}=\frac{0.5m}{0.5} \\ 13=m \end{gathered}[/tex]m = 13 which is greater than 10
Lupe travel more than 10 miles
This is the answer of (b)