Answer:
Step-by-step explanation:
in rectangular form the equation is 
Answer:
d.a cluster sampling
Step-by-step explanation:
This plan exemplifies Cluster sampling. It is a sampling method where populations are placed into different separate groups like here into freshman, sophomore, junior, and senior classes. A random sample of these groups is then selected as here thirty students selected from each group to represent a specific population.<u> It is usually used in that type of research when there is no possible way to find information about a population as a whole.</u>
Answer:
180 degrees
Step-by-step explanation:
3(x + 7) = 9(x - 1)
3(x) + 3(7) = 9(x) - 9(1)
3x + 21 = 9x - 9
<u>- 3x - 3x </u>
21 = 3x - 9
<u>+ 9 + 9</u>
<u>30</u> = <u>3x</u>
3 3
10 = x