Answer:. x = 18
Explanation:
Solve by substitution. Given: y= 12x. Rewrite the original equation y= 180 + 2x to 12x = 180 +2x. Subtract 2x from both sides. 10x = 180. Then divide both sides by 10.
x=18
So once she has sold 18 necklaces, she has covered her costs (180 + 36) and she begins to make a profit.