The local fish market is having a sale on whole fish. the prices are as follows:

You can buy an albacore and a barracuda for$21
You can buy a barracuda and a carp for $24
You can buy a carp and a dogfish for $32
You can buy a dogfish and an eel for $37
You can buy an eel and flounder for $31
You can buy a flounder and a gar for $25
You can buy gar and an albacore for $26

Determine the cost of each individual fish

i understand that
B=21-A
C=24-21+A
D=32-4-A
E=37-28+A
F=31-9-A
G=25-22+A
and A=26-3-?
my question is what variable goes where the ? is. i think its b but i'm not sure

Many of your equations are wrong.

B = 21 - A
C = 24 -(21 -A) = 3 + A
D = 32 - (3 + A) = 29 - A
E = 37 - (29 - A) = 8 + A
F = 31 - (8 + A) = 23 - A
G = 25 - (23 - A) = 2 + A
G + A = 26

The last two equations can be solved for A, which is 12

i still don't understand how you got 12, but thank you for your help!

Combining the last two equations gives you

G + A = (2 + A) + A = 26
2A = 24
Do you see it now?

oh! thanks i get it now

i have the same exact problem and don't get it

To determine the variable that goes in place of the "?" in the equation A = 26 - 3 - ?, we can evaluate the information given.

From the given information, we know that:
- Albacore (A) and Barracuda (B) together cost $21, so A + B = 21.
- Barracuda (B) and Carp (C) together cost $24, so B + C = 24.
- Carp (C) and Dogfish (D) together cost $32, so C + D = 32.
- Dogfish (D) and Eel (E) together cost $37, so D + E = 37.
- Eel (E) and Flounder (F) together cost $31, so E + F = 31.
- Flounder (F) and Gar (G) together cost $25, so F + G = 25.
- Gar (G) and Albacore (A) together cost $26, so G + A = 26.

We can use this information to solve for each variable individually. Let's start by substituting the equations:

From B + C = 24, we know that C = 24 - B.

From C + D = 32, we can substitute C with 24 - B to get (24 - B) + D = 32, yielding D = 8 + B.

Now, substituting D in the equation D + E = 37, we get (8 + B) + E = 37, which simplifies to E = 29 - B.

Next, substituting E in the equation E + F = 31, we find (29 - B) + F = 31, yielding F = 2 + B.

Lastly, substituting F in the equation F + G = 25, we obtain (2 + B) + G = 25, which simplifies to G = 23 - B.

Now we can substitute these values of G, F, E, D, C into G + A = 26, giving (23 - B) + A = 26, which simplifies to A = 3 + B.

We can see that the variable that goes in place of the "?" in the equation A = 26 - 3 - ? is B. Therefore, the correct answer is B.