would you please help me answer this question??? thanks

mary wants to spend $70. at most for gifts but only has 60 cubic inches of space in her suitcase. rings cost $7 and take up 3 cubic inches of space and scarfs are $5 and take up 15 cubic inches. Write a system of four inequalities that model mary's
purchases. Let x = number of rings
and y = number of scarf.

I put:
equation 1: 3x(3 cubic inches)+15x(15 cubic inches) =< 60 cubic inches
equation 2: 7x + 5y =< $70

equation 3 ??

equation 4 ??

To create a system of inequalities that models Mary's purchases, we need to consider the constraints on both the space in her suitcase and the amount of money she wants to spend. Let's break it down step by step:

1. Space Constraint:
The total cubic inches of space taken up by the rings (3 cubic inches each) and scarfs (15 cubic inches each) must be less than or equal to the available space in Mary's suitcase (60 cubic inches). This can be represented as the inequality:

3x + 15y ≤ 60

2. Cost Constraint:
The total cost of rings ($7 each) and scarfs ($5 each) must be less than or equal to the amount of money Mary wants to spend ($70). This can be represented as the inequality:

7x + 5y ≤ 70

However, we still need two more inequalities to consider the non-negativity constraints for the variables x and y.

3. Non-negativity for x:
Since Mary cannot buy a negative number of rings, we have the inequality:

x ≥ 0

4. Non-negativity for y:
Similarly, Mary cannot buy a negative number of scarfs, so we have the inequality:

y ≥ 0

Therefore, the system of four inequalities that models Mary's purchases is:

1. 3x + 15y ≤ 60
2. 7x + 5y ≤ 70
3. x ≥ 0
4. y ≥ 0

These inequalities represent the constraints on both the available space and the budget that Mary has when making her purchases.