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.
Step-by-step explanation:
1 t=16/21
2.m=2
3.n=13/7
4.a=2
5.x=6/17
6.x=15
7.s=21/4
8. t=7/3
9. s=1
10. s=6/61
11. x=1/3
12. r=27/16
13. c=−1
14.m=9/5n
15. j=−117/58
The first answer and the last one
Plug in each number into their designated spots.
Example with (0,5)
0 goes into x and 5 goes into the y variable and this is the equation now:
2*0 +4*5=20
0 times 2 = 0 and 4*5=20
So that is one of the correct answers.
Repeat the process and you find that the last option is also correct.
First computer takes x min. For 1 min it does 1/x part of work.
Second computer takes (x+24) min. For one min it does 1/(x+24) part of work.
Both computers for one min do (1/x+1/(x+24)) part of work.
At the same time, both computers for one min do 1/9 part of work.