Answer: choice B) a35 = -118
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Explanation:
When n = 5, an = 32 as shown in the first column of the table. This means the fifth term is 32. Plug in those values to get
an = a1+d(n-1)
32 = a1+d(5-1)
32 = a1+4d
Solve for a1 by subtracting 4d from both sides
a1 = 32-4d
We'll plug this in later
Turn to the second column of the table. We have n = 10 and an = 7. Plug those values into the formula
an = a1+d(n-1)
7 = a1 + d(10-1)
7 = a1+9d
Now substitute in the equation in which we solved for a1
7 = a1+9d
7 = 32-4d+9d ... replace a1 with 32-4d
7 = 32+5d
5d = 7-32
5d = -25
d = -25/5
d = -5
This tells us that we subtract 5 from each term to get the next term.
Use this d value to find a1
a1 = 32-4d
a1 = 32-4*(-5)
a1 = 32+20
a1 = 52
The first term is 52
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The nth term formula is therefore
an = 52 + (-5)(n-1)
which simplifies to
an = -5n + 57
To check this result, plug in n = 5 to find that a5 = 32. Similarly, you'll find that a10 = 7 after plugging in n = 10. I'll let you do these checks.
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Replace n with 35 to find the 35th term
an = -5n + 57
a35 = -5(35) + 57
a35 = -175 + 57
a35 = -118
The answer is 47 is 25% of 188.
They are the same length,because 3 fr is the same as 12 inches times 3 equals 36 inches
Answer:
a. Plan B; $4
b. 160 mins; Plan B
Step-by-step explanation:
a. Cost of Plan A for 80 minutes:
Find 80 on the x axis, and trave it up to to intercept the blue line (for Plan A). Check the y axis to see the value of y at this point. Thus:
f(80) = 8
This means Plan A will cost $8 for Rafael to 80 mins of long distance call per month.
Also, find the cost per month for 80 mins for Plan B. Use the same procedure as used in finding cost for plan A.
Plan B will cost $12.
Therefore, Plan B cost more.
Plan B cost $4 more than Plan A ($12 - $8 = $4)
b. Number of minutes that the two will cost the same is the number of minutes at the point where the two lines intercept = 160 minutes.
At 160 minutes, they both cost $16
The plan that will cost less if the time spent exceeds 160 minutes is Plan B.
Let us say that the numbers are x and y. The given clues
are:
1. x – y = 16 (so
x is the larger number)
2. y / x = 5 / 7
rewriting eqtn 2 in terms of y:
y = (5/7) x
combining 1 and 2:
x – (5/7) x = 16
(2/7) x = 16
x = 56
y = (5/7) x = 40
So the two numbers are 56 and 40.
