Answer:
Step-by-step explanation:
<u>Key skills needed: Explicit formula, Geometric sequence</u>
1) This is a geometric sequence, meaning a constant (like 6 or 3.5) is being multiplied to every term. First we need to find the constant.
This can be done by doing -42 ÷ 7 or 252 ÷ -42
-42 ÷ 7 equals -6.
252 ÷ -42 also equals -6.
2) This means that constant is -6.
3) The general form for an explicit formula of a geometric sequence is:
--> r means the constant (or common ratio) that is being multiplied.
--> means the first term
--> means the "nth" numbered term (so is the 3rd term, is the 10th term and so on).
--> is just the "n" in minus 1.
4) We can use this formula to create an explicit formula for the geometric sequence in the problem.
--> (Since we got -6 as the constant/common ratio).
--> (Since 7 is the 1st term)
This means that our formula would be -->
<em>Hope you understood and have a nice day!! :D</em>
9514 1404 393
Answer:
a) average rate = (total distance)/(total time)
b) Rave = 2·R1·R2/(R1 +R2)
c) cheetah's average rate ≈ 50.91 mph
Step-by-step explanation:
a) Let AB represent the distance from A to B. Let t1 and t2 represent the travel times (in hours) on leg1 and leg2 of the trip, respectively. Then the distances traveled are...
First leg distance: AB = 70·t1 ⇒ t1 = AB/70
Second leg distance: AB = 40·t2 ⇒ t2 = AB/40
The average rate is the ratio of total distance to total time:
average rate = (AB +AB)/(t1 +t2)
average rate = 2AB/(AB/70 +AB/40) = 2/(1/70 +1/40) = 2(40)(70)/(70+40)
average rate = 560/11 = 50 10/11 . . . mph
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No equations are given, so we cannot compare what we wrote with the given equations. In each step of the solution, we have used the rules of algebra and equality.
b) For two rates over the same distance (as above), the average is their harmonic mean:
average rate = 2r1·r2/(r1+r2)
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c) The cheetah's average rate was 50 10/11 mph ≈ 50.91 mph.
Answer:
562 child tickets were sold
217 adult tickets were sold
Step-by-step explanation:
A festival charges $3 for children admission and $5 for adult admission
At the end of the festival they have sold a total number of 779 tickets for $2771
Let x represent the child ticket
Let y represent the adult ticket
x + y= 779..............equation 1
3x + 5y= 2771..........equation 2
From equation 1
x + y = 779
x= 779 -y
Substitute 779-y for x in equation 2
3x + 5y= 2771
3(779-y) + 5y= 2771
2337 - 3y + 5y= 2771
2337 +2y= 2771
2y= 2771 -2337
2y = 434
y = 434/2
y = 217
Substitute 217 for y in equation 1
x + y= 779
x + 217= 779
x = 779-217
x= 562
Hence 562 child tickets were sold and 217 adult tickets were sold
Answer:
31.5
Step-by-step explanation: