Tyrel and Dalia bought some pens and pencils. Tyrel bought 4 pens and
5 pencils, which cost him $6.71. Dalia bought 5 pens and 3 pencils, which cost
her $7.12. Let a equal the price of a pen. Let b equal the price of a pencil.
a. Write an equation that relates the number of pens and pencils Tyrel bought
to the amount he paid for them.
b. Write an equation that relates the number of pens and pencils Dalia bought
to the amount she paid for them.
c. Solve the system you wrote for parts (a) and (b) to find the price of a pen
and the price of a pencil.