Take both mixed numbers (a whole number plus a fraction) and turn them into improper fractions ( a numerator (top number) bigger than the denominator (bottom number). To do this, multiply the denominator by the whole number, and add the result to the numerator.
5 5/8 will become 45/8
1 1/2 will become 3/2.
Area is length* width, so width would be Area/ length. So 45/8 is the area and 3/2 is the length. Now you have (45/8)/(3/2). To divide fractions, take the second fraction and flip the numerator and denominator, forming the reciprocal (2/3). Now multiply 45/8 and 2/3
The result is 90/24, and simplifying would get 15/4, or 3 3/4. This is the width(or length)