She would need to but 48 videos to get the cash prize. Hope this helps :)
The value of the expression would decrease because if you add more to the smallest number in the subtraction problem the value or the answer decreases
Perimeter=|1+|2+|3
=12.5+10.6+9.5=32.6inches
Y = 1/3 x - 10 . . . (1)
2x + y = 4 . . . . . . (2)
Putting (1) into (2) gives, 2x + 1/3 x - 10 = 4
7/3 x - 10 = 4
7/3 x = 4 + 10 = 14
x = (3 x 14)/7 = 6
From (1), y = 1/3(6) - 10 = 2 - 10 = -8
x = 6, y = -8
