Answer:
x=-9
Step-by-step explanation:
x+5=2(7+x)
x+5=14+2x
x-2x=14-5
-1x=9
x=-9
Answer:
not sure what type you mean but here are options
Step-by-step explanation:
30+4=34
thirty-four
Answer:
C. 
Step-by-step explanation:
Recall: SOHCAHTOA
Thus,

Reference angle = 28°
Adjacent = 15
Hypotenuse = 17
Plug in the values

Answer: It represents the area of the two circular sides ("lids")
Explanation:
Imagine you made a cylinder out of 3 pieces of paper. The cylinder can be decomposed into two circular shapes (radius r) and one rectangular piece with two side lengths: one is "h", the other has to be long enough to go around each of the disks, so it has to be 2*pi*r long.
So the term 2*pi*r*h is the area of the rectangular piece and pi*r^2 is the area of each of the "lids" Since there are two of those, the term 2*pi*r^2 represents the area of the bottom and top lids.