Answer:
c. 
Step-by-step explanation:
Given,
Number of bacterias who alive for at least 30 days = 5,
Bacterias who alive for 2 days = 10,
Died bacterias = 10,
Total bacterias = 5 + 10 + 10 = 25,
Ways of choosing a bacteria =
=
= 25,
While, ways of choosing of a bacteria who will live after 1 week =
=
= 5,
Hence, the probability it will still be alive after one week =
= 
OPTION C is correct.
Answer:
Tn=13n-18
Step-by-step explanation:
Tn=-5(n-1)13
Simplify
this is using the a+(n-1)d
Answer:
Step-by-step explanation:
Ok I think it is 8 though
You can use the result here:
brainly.com/question/11990269
This identity suggests that

From here, you can use the sum/difference identities for cosine.



Apply these carefully to the right hand side and it should reduce quite nicely to the same expression on the left.