Problema Solution

on a buying trip in los angeles,rosaria perez ordered 120 pieces of jewelry: a number of bracelets at $7 each and a number of necklaces at $9 dollars each. She wrote a check for $1000 dollars to pay for the order.How many bracelets and how many necklaces did rosaria purchase?

Answer provided by our tutors

You will need to create two expressions to represent the problem.

 

For example, we have bracelets (x) and necklaces (y), so we know:

x + y = 120

 

We also know that:

7x + 9y = $1000

 

So now all we need to do is use the first expression (x+y=120) and set it equal to x (ie. x = 120 - y).

Now we plug this into our second equation:

7x + 9y =$1000

7(120 - y) + 9y =$1000

Now distribute the 7:

840 - 7y + 9y =$1000

840 + 2y =$1000

2y = 160

y = 80

 

Now all you have to do is plug this y value back into one of your equations above to solve for x!