7 is the most amount of books that would fit on a 18 inch shelf
To find the box to the top left, we can multiple the sides like rectangles. To find the top left box, we can multiply -1 and 0.5y to get -0.5y.
To find the box on the bottom right, we can multiply the sides like rectangles again. To find the bottom right box, we can multiply 24x and 3 to get 72x.
2x^2 - y when x + 3 and y = -2
2(3)^2 - (-2)
2(9) + 4
18 + 4
22
Hope this helps,
Brian