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
sin(x) = opp/hyp
cos(x) = adj/hyp
tan(x) = opp/adj
sin(x) = 3.9/8.1
sin(x) = 0.481
Inverse sin of 0.481 = 28.8 degrees
Each answer should be between 0 and 90 :)
Answer:
answer is C
Step-by-step explanation:
because -1<5
and not 6<-1 or -5>5
Answer:
2 is the answer I did this once in class
Answer:
The lines are not parallel since their slopes are different( 2/5 and 3/5)
Step-by-step explanation:
