Answer: he made 4 bracelets and 3 necklaces.
Step-by-step explanation:
Let x represent the number of bracelets made.
Let y represent number of necklaces made.
The jeweler made a total of 7 bracelets and necklaces. This means that
x + y = 7
The amount of gold in each bracelet is 6 grams and the amount of gold in each necklace is 16 grams. The total amount of gold used was 72 grams. This means that
6x + 16y = 72 - - - - - - - - - - - - 1
Substituting x = 7 - y into equation 1, it becomes
6(7 - y) + 16y = 72
42 - 6y + 16y = 72
- 6y + 16y = 72 - 42
10y = 30
y = 30/10
y = 3
x = 7 - y = 7 - 3
x = 4