Answer: 
Step-by-step explanation:
Answer:
The length of the rectangle is 13 inches and its width (13 + 12) is 25 inches.
Step-by-step explanation:
You have to consider the formula of the perimeter = 2·length + 2·width.
If we call "x" to the length ⇒ width = x + 12 .
Perimeter = 2x + 2·(x + 12) ⇒ Perimeter = 2x + 2x + 24
⇒Perimeter = 4x + 24. ⇒ 76 = 4x + 24 ⇒ 76 - 24 = 4x ⇒52 = 4x
⇒ 52/4 = x ⇒ x = 13.
So, the length of the rectangle is 13 inches and its width (13 + 12) is 25 inches.
Answer:
It would be C
Step-by-step explanation:
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
