Answer:
$16.60
Step-by-step explanation:
Setup the formula to calculate the cost of each pound of salmon and swordfish for the 2.5 pounds of salmon (x) and 1.25 pounds of swordfish (y) which is equal to $31.25
2.5x + 1.25y = 31.25
Setup a formula to figure out how much a single pound of swordfish (y) is. The problem states it cost $0.20 less than a pound of salmon (x).
y = x - .20
Plug the y = x - .20 into the first equation.
2.5x + 1.25(x - .20) = 31.25
Distribute the 1.25 by multiplying it with x and -.20
2.5x + 1.25x - .25 = 31.25
Combine like terms, x on the left side
3.75x - .25 = 31.25
Add .25 to both sides to get x on one side
3.75x = 31.50
Divide both sides by 3.75 to get x by itself
x = 8.4
So, each pound of salmon, x, cost $8.40 per pound
Use y = x - .20 and plug in x = 8.4 to figure out how much a pound of swordfish cost.
y = 8.4 - .20
So, a pound of swordfish cost $8.20 per pound
The question wants to know the combined cost, z, of 1 pound of salmon, x, and 1 pound of swordfish, y.
x + y = z
8.4 + 8.2 = 16.6
The combined cost of 1 pound of salmon and 1 pound of swordfish is $16.60
