21 students sleep for 9 hours each night
<em><u>Solution:</u></em>
Given that, Mr.Lee wants to survey 20 of the 210 students in seventh grade about the hours they sleep each night
He finds 2 of the 20 students surveyed sleep for 9 hours each night
Therefore, 2 out of 20 students sleep for 9 hours each night
Find out the percentage of 2 out of 20
Thus 10 % of 210 students sleep for 9 hours each night
Find out 10 % of 210
Thus 21 students sleep for 9 hours each night
Answer:
3/ 1 divided by 11/12 = 3 and 3/11.
Step-by-step explanation:
3/5 can’t be simplified I think.
7/4 is a improper fraction, and 7/4 as a mixed fraction is 1 and 3/4
Answer:
nth term = 2n^2 - 3n - 6.
Step-by-step explanation:
n = 1 2 3 4 5 6 7
- 7 -4 3 14 29 48 71
Differences 3 7 11 15 19 23
Differences 4 4 4 4 4
So the first term in the Rule is 2n^2
Subtracting the values of 2n^2 from the original terms:
- 7 -4 3 14 29 48 71
2n^2 2 8 18 32 50 72 98
Subtrct -9 -12 -15 -18 -21 -24 -27
-3 -3 -3 -3 -3 -3
So we have -3n and the last term is -6 because -7 = 2(1)^2 -3 - 6 and the other terms fit this pattern as well.
Answer:
plot ab is right just had the test
Answer:
D
Step-by-step explanation:
to find this with your calculator
![\left[\begin{array}{ccc}5&-5&2\\1&5&-6\\1&4&-5\end{array}\right] ^{-1} \left[\begin{array}{ccc}21\\24\\21\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D5%26-5%262%5C%5C1%265%26-6%5C%5C1%264%26-5%5Cend%7Barray%7D%5Cright%5D%20%5E%7B-1%7D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D21%5C%5C24%5C%5C21%5Cend%7Barray%7D%5Cright%5D)
it will give you [5 -1 -4]
