Let x represent number of bracelets and y represent number of necklaces.
We have been given that a jeweler made 7 more necklaces than bracelets. This means that number of necklaces will be
. We can represent this information in an equation as:

We have been given that the amount of gold in each bracelet is 6 grams, so amount used for x bracelets would be
grams.
We are also told that the amount of gold in each necklace is 16 grams, so amount used for y necklaces would be
grams.
Since the jeweler used 178 grams of gold, so we will equate the amount of gold used in x bracelets and y necklaces with 178 as:

Therefore, our required system of equations would be:

