Answer:
8
Step-by-step explanation:
That is the quetion that sal khan explaind in the vid BOI
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
Answer:
4 and 5
Step-by-step explanation:
Let the numbers be x and y
If their sum is 9, hence;
x + y = 9 ....1
When reversed
10y+x = 2(10x+y)
10y+x = 20x + 2y
10y - 2y = 20x - x
8y = 19x
y = 10x/8 ...2
Substitute equation 2 into 1;
From 1;
x+y = 9
x +(10x/8) = 9
18x/8 = 9
18x = 72
x = 72/18
x = 4
Since x+y =9
y = 9-x
y =9-4
y = 5
Hence the numbers are 4 and 5
<span>C. E(n)=5n+42
5 times the number of people + 7 times 6
</span>
Answer:t= 9
Step-by-step explanation: 10t =90
divide 10 on both sides
so 10t /10 and 90/10
which means t=9
