Cameron spent $13.50 at a pet store buying fish for his aquarium. He bought a bag of 14 fish that contained a combination of guppies and goldfish. Goldfish cost $1.65 a piece and guppies cost $0.45 a piece. How many of each type of fish did Cameron buy?

x = # of guppies

y = # of goldfish
x + y = 14
1.65 y + 0.45 x = 13.50
Substitute 14-x for y and solve for x.
23.1 - 1.65 x + 0.45 x = 13.50
1.20 x = 9.60
yada yada yada

the answer is 6 goldfish and 8 guppies.

To solve this problem, we can set up a system of equations based on the given information.

Let's use the variables:
G = the number of goldfish
P = the number of guppies

We can translate the given information into equations:

1. The total number of fish: G + P = 14 (equation 1)
2. The total cost of fish: 1.65G + 0.45P = 13.50 (equation 2)

Now we can solve this system of equations to find the values of G and P.

We'll start by solving equation 1 for G:
G = 14 - P

Next, substitute the value of G into equation 2:
1.65(14 - P) + 0.45P = 13.50

Distribute 1.65:
23.1 - 1.65P + 0.45P = 13.50

Combine like terms:
23.1 - 1.2P = 13.50

Subtract 23.1 from both sides:
-1.2P = -9.6

Divide by -1.2:
P = 8

Now, substitute the value of P back into equation 1 to find G:
G + 8 = 14
G = 6

Therefore, Cameron bought 6 goldfish and 8 guppies for his aquarium.