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
Answer:
For x^2 + 5x - 14 = 0
x1= -7, x2 = 2
For x^2 + 5x + 6 = 0
x1 = -3, x2 = -2
Step-by-step explanation:
Pls see attached....
Answer:
No
Step-by-step explanation:
There isn't enough space the room is too small
Answer: -7=0 --> Impossible
Step-by-step explanation:
2x-7+x-11= 3x-11
2x+x-7-11=3x-11
3x-18=3x-11
3x-18+11=3x
3x-7-3x=0
-7=0
Impossible
Your drawing was much more helpful and informative than your statements in words and symbols.
I see that you want to evaluate (3/2)^2 times (8/15)^2.
You could combine these two expressions into one, as follows:
3*8
( ----------- )^2
2*15
This, in turn, can be simplified by reduction:
( 4/5 )^2. Expanded, this result gives us 16/25.
Next problem
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( 9/4 )^4 * ( 4/3 )^3
9^4 4^3
First, focus on ( ------- ) * ( ----------- )
4^4 3^3
Now reduce 4^3 / 4^4: The end result is 1/4.
Reduce 9^4 / 3^3. To do this, rewrite that 9 as (3^2), resulting in:
3^8 / 3^3. The end result is 3^5.
Putting this expression back together, we get 3^5 / 4 (answer)
