A = b+5
ab = 3300
(b+5)b = 3300
b² +5b -3300 = 0 (quadratic formula)
b=55
a=60 (by first relation)
25/80 + 24/80 = 49/80. 16 and 20 both go into 80. !6 goes in 5 times so you multiply 5 by 5. 20 goes into 80 4 times so you multiply 4 by 4. 24/80 + 25/80 = 49/80.
Answer:
You need four squares.
On the top left square, you put the number 20 over it, and the number 30 to its left. Put the number 600 in the square.
Next, the bottom left square. But the number 4 on the left side of the square, and put the number 80 in the square.
Now, the top right box. put the number 8 over it, and fill it with the number 240.
Last, fill the bottom right square with the number 32.
The vertex of a parabola is its highest or lowest point. Here, it is the lowest point, which happens right at the bottom of the U-shape—at (1, –4). Therefore, the answer is C.