w e can writhe a equation
[tex]y=3x+1[/tex]where y is the total of recipes and x the weeks
y=40 according to the text
so, we can replace y and solve x to know the weeks
[tex]\begin{gathered} 40=3x+1 \\ 40-1=3x \\ x=\frac{39}{3} \\ x=13 \end{gathered}[/tex]so she will know 40 appetizer recipes on 13 weeks