If 5 dollars and 35 crowns is equivalent to 7 pounds, and 4 dollars and 4 pounds is equivalent to 56 crowns, 1 pound and 28 crowns is equivalent to how many dollars?

1 pound and 28 crowns is equivalent to 7 dollars.

Explanation:

Let the dollars be x , crowns be y and pound be z.

To find = 1z + 28y = ? (value in dollars)

5 dollars and 35 crowns is equivalent to 7 pounds

...[1]

4 dollars and 4 pounds is equivalent to 56 crowns

...[2]

Using value of from [1] here in [2]:

Now:

1z + 28y = ?

1 pound and 28 crowns is equivalent to 7 dollars.