Answer:
C
Step-by-step explanation:
In general for arithmetic sequences, recursive formulas are of the form
aₙ = aₙ₋₁ + d,
and the explicit formula (like tₙ in your problem), are of the form
aₙ = a₁ + (n - 1)d,
where d is the common difference. So converting between the two of these isn't so bad. In this case, your problem wants you to have an idea of what t₁ is (well, every answer says it's -5, so there you are) and what tₙ₊₁ is. Using the formulas above and your given tₙ = -5 + (n - 1)78, we can see that the common difference is 78, so no matter what we get ourselves into, the constant being added on at the end should be 78. That automatically throws out answer choice D.
But to narrow it down between the rest of them, you want to use the general form for the recursive formula and substitute (n + 1) for every instance of n. This will let you find tₙ₊₁ to match the requirements of your answer choices. So
tₙ₊₁ = t₍ₙ₊₁₎₋₁ + d ... Simplify the subscript
tₙ₊₁ = tₙ + d
Therefore, your formula for tₙ₊₁ = tₙ + 78, which is answer choice C.
Answer:
2
Step-by-step explanation:
-6 divided by a positive number would make it a positive number welcome
Answer:
Step-by-step explanation:
9a - 8 = 2a - 2b
7a - 8 = -2b
7a = 8 - 2b
a = (8 - 2b)/7
Answer:
0.1137= 11.37%
Step-by-step explanation:
Assuming there are 365 days in one year and every people have 1 birthday, then the chance for two people to have the same birthday is 1/365 and the chance they are not is 364/365. We are asked the chance for at least one match among 44 people. The opposite of the condition is that we have 0 matches and easier to calculate. The calculation will be:
P(X>=1)= ~P(X=0) = 1
P(X>=1)=- P(X=0)
P(X>=1)=1 - (364/365)^44
P(X>=1)=1- 0.8862
P(X>=1)=11.37%
To find the number of words she can read per minute, we would do 560 divide by 7 minutes
560/7 = 80 words per minute
Hope this helps
