ANSWER
[tex]\$0.75[/tex]EXPLANATION
Let the cost of the pen be x.
Let the cost of the pencil be y.
The pen costs 3 times as much as the pencil. This implies that:
[tex]x=3y[/tex]The cost of 4 pencils and 3 pens is $9.75. This implies that:
[tex]4y+3x=9.75[/tex]Substitute the first equation into the second equation:
[tex]4y+3(3y)=9.75[/tex]Simplify and solve for y:
[tex]\begin{gathered} 4y+9y=9.75 \\ 13y=9.75 \\ \Rightarrow y=\frac{9.75}{13} \\ y=\$0.75 \end{gathered}[/tex]That is the cost of a pencil.
