Chapter 3 - Equations and Problem Solving - 3.2 - Equations and Problem Solving - Problem Set 3.2 - Page 107: 69

The cost of the ring to the jeweler was 300.

Let X represent the cost of the ring to the jeweler. Twice the cost of the ring to the jeweler means 2X. 50 less than twice the cost of the ring to the jeweler means 2X - 50. The price of a diamond ring at 550. So: 2X - 50 = 550 Add 50 to both sides 2X = 600 Divide both sides by 2 X = 300