We keep the 2x^2 because we can only subtract something from that if it also is squared. From there, we subtract the 7x from 2x^2-11. Since there is no previous x's in the 2x^2-11, we just make it -7x. So, without even continuing the problem, we see that A) is the correct answer because it is the only one with -7x.
Answer:
i think the difference in height from the top to the bottom is 8ft
Answer: There are 140 adults and 40 children.
Step-by-step explanation:
Let 2x = Number of children
7x = Number of adults.
As there are 100 more adults than children.
That means, 
Number of children = 2 (20)=40
Number of adults = 7(20) = 140
Hence, there are 140 adults and 40 children.
9/6 = 1.5
24/1.5 = 16
triangle DEF has a primeter of 16 inches
Area = 299*34 = 10166 ft^2
Cost = 10166 * 11 = $111,826 (answer)
