SOLUTION: A gold and copper bracelet weighs 238 grams. The volume of the bracelet is 15 cubic cenimeters. Gold weighs 19.3 grams per cubic cenimeter and copper weighs 9 grams per cubic cenim

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: A gold and copper bracelet weighs 238 grams. The volume of the bracelet is 15 cubic cenimeters. Gold weighs 19.3 grams per cubic cenimeter and copper weighs 9 grams per cubic cenim      Log On


   

Question 232750: A gold and copper bracelet weighs 238 grams. The volume of the bracelet is 15 cubic cenimeters. Gold weighs 19.3 grams per cubic cenimeter and copper weighs 9 grams per cubic cenimeter. How many grams of copper are mixed with the gold?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let c = grams of copper in bracelet
Let g = grams of gold in bracelet
given:
(1) c+%2B+g+=+238 g
(2) g%2F19.3+%2B+c%2F9+=+15 cm3
This is 2 equations and 2 unknowns, so it's solvable
Multiply both sides of (2) by 19.3%2A9+=+173.7
(2) 9g+%2B+19.3c+=+2605.5
Multiply both sides of (1) by 90 and subtract from (2)
(2) 90g+%2B+193c+=+26055
(1) -90g+-+90c+=-+21420
103c+=+4635
c+=+45
45 grams of copper are mixed with the gold
check answer:
(1) c+%2B+g+=+238
45+%2B+g+=+238
g+=+193
(2) g%2F19.3+%2B+c%2F9+=+15
(2) 193%2F19.3+%2B+45%2F9+=+15
10+%2B+5+=+15
OK