Answer:
465
Step-by-step explanation:
1 + 2 + 3 + ... + n = n(n + 1)/2
1 + 2 + 3 + ... + 30 = 30(31)/2 = 465
Each grid line is 2 units
A is located on X = -10, B is located on X = 2
the distance between A and B = 12 units
A is located on Y = 2, D is located on Y = -6
the distance between A and D = 8 units
the dimension of the rectangle is 12 by 8
The answer would be 45 weeks, since you do 530-80 since that is the part the parents will foot, which will be 450 left. Then you do that divided by 10 since you plan to save 10 dollars a week and therefore are left with 45 weeks.