Let the length of the original strip of rawhide be L inches.
Fluffy chews the rawhide for 6 minutes, so she chews a length of 6 x 2 = 12 inches.
Let the length of rawhide left be (L - 12) inches.
Fido chews the remaining rawhide, so he chews a length of 5x minutes, where x is the number of minutes he chews. The total length of rawhide he chews is (L - 12) - 5x.
Fido and Fluffy chewed half of the rawhide each, so they each chewed a length of L/2 inches.
Putting it all together:
Fluffy chews a length of 12 inches in 6 minutes, so her chewing rate is 2 inches per minute.
Fido chews a length of (L/2 - 12) inches in x minutes, so his chewing rate is (L/2 - 12)/x inches per minute.
In total, they chewed a length of L/2 inches.
We can write an equation to express the total length of rawhide they chewed:
12 + (L/2 - 12)/x * (x + 6) = L/2
Simplifying this equation:
12 + (L/2 - 12)(1 + 6/x) = L/2
Multiplying both sides by 2:
24 + (L - 24)(1 + 6/x) = L
Expanding the brackets:
24 + L - 24 + 6L/x - 6 = L
Simplifying:
6L/x = 6
L = x
So the original strip of rawhide was 6 x 2 = 12 inches long.