A local fish market is selling fish and lobsters by the pound. The fish, f, costs $6.50 a pound, while the lobster, l, costs $9.50 a pound. The fish market sells 20.5 pounds and makes $155.75.

Question

How many pounds of fish and pounds of lobster did the market sell?

Enter a system of equations to represent the situation, then solve the system.

Answer 1

Let "F" be the number of pounds of fish sold by the market.

Let "L" be the number of pounds of lobster sold by the market.

Writing the system of equations:

F + L = 20.5

6.5F + 9.5L = 155.75

From 1st equation:

F = 20.5 - L

Substitute this expression into the 2nd equation:

6.5(20.5 - L) + 9.5L = 155.75

L = 7.5 (pounds)

F = 13 ( pounds)

Answer 2

F+L = 20.5

6.5F + 9.5L = 155.75

6.5F + 6.5L = 133.25

3L = 22.5

L= 7.5 pounds of lobster

F = 13.5 pounds of fish

Answer 3

f+l=20.5

6.50f+9.50l=155.75

Solve for f and l.