His rate is 4.5 miles per hour. It would take him 4 hours to hike 18 miles. He would have traveled 31.5 miles in 7 hours.
Y = 2x-3
The second line will have its Y-Intercept at -3 and its slope will be up 2 and over 1 which will allow it to go through (4,5) and the line will be parallel to Y = 2x+2
Answer:1st one 2nd one and 8th
Step-by-step explanation:
Since the constant has been moved to the left side, you can move on to the next step which is adding (b/2)² to both sides of the equation.
h² + 14h + (14/2)² = -31 + (14/2)²
Simplify the parenthesis and exponent.
h² + 14h + 7² = -31 + 7²
h² + 14h + 49 = -31 + 49
h² + 14h + 49 = 18
Factor the expression of the left.
(h + 7)(h + 7) = 18
Take the square root of both sides.
√(h + 7)(h + 7) = ± √9 • 2
(h + 7) = ± 3√2
h + 7 = ± 3√2
Subtract 7 from both sides.
You solutions are:
h = -7 + 3√2 → -2.7573 → -2.76
h = -7 - 3√2 → -11.2426 → -11.24
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