Let's call the length of the longer rope piece x and the length of the shorter rope piece y. We know that:
x + y = 5 (the total length of the rope is 5 feet)
And from the problem statement, we have:
3x - 7 = 5y
Now we can use the first equation to solve for y:
y = 5 - x
Substituting this expression for y into the second equation:
3x - 7 = 5(5 - x)
Expanding the right side:
3x - 7 = 25 - 5x
Adding 5x to both sides:
8x - 7 = 25
Adding 7 to both sides:
8x = 32
Dividing both sides by 8:
x = 4
So the length of the longer rope piece is 4 feet.