Answer:
21, 14
Step-by-step explanation:
by dividing 3 from 42 you get 14, and by adding 7 you get 21. And finally by devifing 3 from 21 you get 7 and by adding 7 to 7 you get 14.
Answer:
I would find it by multiplying -3x-2 and getting six. Then I would multiply -1x2 and get -2 then I would add six and -2 and get 4.
Step-by-step explanation:
The answer to your question is C. Mark brainliest if you can.
Answer:
8 days
Step-by-step explanation:
On day 8, Isabella will save 256 nickels, bringing her total to 510.
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The number of nickels saved on day n is 2^n. The total is 2^(n+1)-2.
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The above can be written down from your knowledge of binary sequences. If you want a more formal development, read on.
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The number of nickels saved on day n is a geometric sequence with first term 2 and common ratio 2. The n-th term of the sequence is ...
an = a1·r^(n-1) = 2·2^(n-1) = 2^n
The sum of n terms of the sequence is ...
S = a1(r^n -1)/(r -1) = 2(2^n -1)/(2-1)
S = 2^(n+1) -2
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We want S > 500, so ...
500 < 2^(n+1) -2
502 < 2^(n+1)
251 < 2^n
log(251) < n·log(2)
n > log(251)/log(2)
n > 7.97 . . . . . . . . 8 days or more to save more than 500 nickels
