Final answer:
By defining a system of equations based on the cost and quantity of fruits bought by Luke, we solve for x (the number of apples) and y (the number of bananas), resulting in Luke purchasing 5 apples and 8 bananas.
Step-by-step explanation:
The student's question involves solving a system of linear equations to determine the number of apples and bananas Luke bought at a grocery store. We are given the total cost of the fruits and the total number of fruits. We set up our system of equations where x represents the number of apples and y represents the number of bananas. We know each apple costs $1 and each banana costs $0.50.
The two equations that describe this scenario are:
- x + y = 13 (total number of fruits)
- $1x + $0.50y = $9 (total cost of fruits)
Multiplying the second equation by 2 to eliminate the fraction, we get 2x + y = 18. Now we subtract the first equation from this new equation to obtain: x = 5. This implies that Luke bought 5 apples. Substituting the value of x into the first equation, we get 5 + y = 13, which gives us y = 8. This means Luke bought 8 bananas.
To summarize, Luke bought 5 apples and 8 bananas.