Answer:
All of them
Step-by-step explanation:
According to the ratio test, for a series ∑aₙ:
If lim(n→∞) |aₙ₊₁ / aₙ| < 1, then ∑aₙ converges.
If lim(n→∞) |aₙ₊₁ / aₙ| > 1, then ∑aₙ diverges.
(I) aₙ = 10 / n!
lim(n→∞) |(10 / (n+1)!) / (10 / n!)|
lim(n→∞) |(10 / (n+1)!) × (n! / 10)|
lim(n→∞) |n! / (n+1)!|
lim(n→∞) |1 / (n+1)|
0 < 1
This series converges.
(II) aₙ = n / 2ⁿ
lim(n→∞) |((n+1) / 2ⁿ⁺¹) / (n / 2ⁿ)|
lim(n→∞) |((n+1) / 2ⁿ⁺¹) × (2ⁿ / n)|
lim(n→∞) |(n+1) / (2n)|
1/2 < 1
This series converges.
(III) aₙ = 1 / (2n)!
lim(n→∞) |(1 / (2(n+1))!) / (1 / (2n)!)|
lim(n→∞) |(1 / (2n+2)!) × (2n)! / 1|
lim(n→∞) |(2n)! / (2n+2)!|
lim(n→∞) |1 / ((2n+2)(2n+1))|
0 < 1
This series converges.
If the value was initially v, then after a year it is 0.75v, after 2 years it’s 0.75²v, and so on. So after 6 years it’s 0.75⁶v.
So 0.75⁶v=7500, and v=7500/0.75⁶=$42,139.92 approximately. This is close to $42,140.
2(21x − 7) + 4(3x + 2) = 6(2x + 9) + 3
42x - 14 + 12x + 8= 12x + 54 + 3
54x - 6= 12x + 57
54x=12x + 63
42x=63
x= 63/42
x= 3/2
11. 6 + 5 * 2 + (-3)
6 + 10 - 3
16 - 3
13 <==
12. 67 + 84 - 12 * 4 / 16
67 + 84 - 48/16
67 + 84 - 3
148 <==
13. -5 * -6 - 25/5 - 2
30 - 5 - 2
23 <==
14. 18 - (9 + 3) + 2^3
18 - 12 + 8
14 <==
15. -24 / -6 * 2
4 * 2
8 <==
16. 8 [ (26 + 10) - 4(3 + 2)]
8 [ (36 - 4(5)]
8 [ 36 - 20 ]
8 [ 16 ]
128 <==
17. 6 * 3 / 9 * 2 + 1
18/9 * 2 + 1
2 * 2 + 1
4 + 1
5 <==
18. (9 - -4)(-8 - -7)
(9 + 4)(-8 + 7)
13 * -1
-13 <==
Answer:
b
Step-by-step explanation:
i took the test
