Answer:
It's the bottom right, the rectangle
First, subtract 5 from both sides, leaving you with 5

- 30x - 5 = 0
If you use the quadratic formula (a=5), (b=-30), (c=-5)
x=-b +/- √b²-4ac / 2a
x= -(30) +/- √(30)² - 4(5) * (-5) / 2(5)
x= 30 +/- √1000 / 10
x = 3 +/- √10
Lst question: x = 5, y = 7
2nd question: x = -1, y = 5
3rd question: x = 98, y = 80
The Volume of the box has to equal 64
because all the sides have to equal 12
and 12/3 = 4