Final answer:
To find the cost of 5 subway tickets and 2 express bus tickets, solve the system of equations for x and y to get x = 2 and y = 4. The cost would be $18.
Step-by-step explanation:
To find the cost of 5 subway tickets and 2 express bus tickets, we can use a system of equations. Let's represent the cost of a subway ticket as 'x' and the cost of an express bus ticket as 'y'.
From the given information, we can write the following two equations:
6x + 4y = 24 (equation 1)
3x + 7y = 27 (equation 2)
Now, we can solve this system of equations to find the values of 'x' and 'y'.
By solving the system of equations, we find that x = 2 and y = 4.
Therefore, the cost of buying 5 subway tickets and 2 express bus tickets would be 5 * 2 + 2 * 4 = 10 + 8 = $18.