Final answer:
The correct inequality for Mary's sales goal is b. 6x+10y≥120 with solutions such as (5, 9), (10, 6), and (15, 3), which all satisfy the condition of earning at least $120.
Step-by-step explanation:
The correct answer to the problem is b. 6x+10y≥120 which means Mary needs to make at least $120 from selling bracelets and necklaces. To satisfy this condition, she can sell different combinations of bracelets (x) and necklaces (y) as long as the total amount from sales is equal to or greater than $120. Let's check the given solutions:
- (5, 9) - This means 5 bracelets and 9 necklaces, which gives a total of (5*$6) + (9*$10) = $30 + $90 = $120. This meets the goal.
- (10, 6) - This means 10 bracelets and 6 necklaces, which gives a total of (10*$6) + (6*$10) = $60 + $60 = $120. This also meets the goal.
- (15, 3) - This means 15 bracelets and 3 necklaces, which gives a total of (15*$6) + (3*$10) = $90 + $30 = $120. This too meets the goal.
Therefore, solutions (5,9), (10,6), and (15,3) are all valid and demonstrate the different combinations of bracelets and necklaces Mary can sell to reach her sales goal.