Answer: Let's call the number of large boxes purchased "L" and the number of small boxes purchased "S".
From the problem, we know that:
Each small box has 100 nails, so the total number of nails from the small boxes is 100S.
Each large box has 450 nails, so the total number of nails from the large boxes is 450L.
The contractor bought 3 more small boxes than large boxes, so S = L + 3.
The total number of nails purchased is 2500, so 100S + 450L = 2500.
We can use the second equation to solve for one of the variables in terms of the other. For example, we can solve for L:
100S + 450L = 2500
Substituting S = L + 3:
100(L + 3) + 450L = 2500
Expanding the parentheses:
100L + 300 + 450L = 2500
Combining like terms:
550L + 300 = 2500
Subtracting 300 from both sides:
550L = 2200
Dividing both sides by 550:
L = 4
So the contractor purchased 4 large boxes of nails.
We can use the equation S = L + 3 to find the number of small boxes purchased:
S = L + 3 = 4 + 3 = 7
So the contractor purchased 7 small boxes of nails.
Therefore, the contractor purchased 4 large boxes and 7 small boxes of nails.
Step-by-step explanation: