4 -> 1 -> 2 -> 3 -> 6 -> 5 -> 7 -> 8

Số phần tử của tập hợp E là:

\(\left(39-1\right):2+1=20\) (phần tử)

Số phần tử của tập hợp F là:

\(\left(195-5\right):5+1=39\) (phần tử)

Số phần tử của tập hợp G là:

\(\left(115-3\right):2+1=57\) (phần tử)

16. B
17. C
18. A
19. C
20. A
21. B
22. C
23. D
24. D
25. B
26. A
27. B
28. D
29. C
30. D
31. A
32. A
33. C
34. A
35. B

\(x^3-8y^3-27z^3-18xyz\)

\(=x^3+\left(-2y\right)^3+\left(-3z\right)^3-3x.\left(-2y\right).\left(-3z\right)\)

\(=\left(x-2y\right)^3-3x.\left(-2y\right)\left(x-2y\right)+\left(-3z\right)^3-3x.\left(-2y\right).\left(-3z\right)\)

\(=\left[\left(x-2y\right)^3+\left(-3z\right)^3\right]+\left[6xy\left(x-2y\right)-6xy.3z\right]\)

\(=\left(x-2y-3z\right)\left[\left(x-2y\right)^2+\left(x-2y\right)3z+\left(3z\right)^2\right]+6xy\left(x-2y-3z\right)\)

\(=\left(x-2y-3z\right)\left[\left(x-2y\right)^2+\left(x-2y\right)3z+\left(3z\right)^2+6xy\right]\)

\(=\left(x-2y-3z\right)\left(x^2-4xy+4y^2+3xz-6yz+9z^2+6xy\right)\)

\(=\left(x-2y-3z\right)\left(x^2+4y^2+9z^2+2xy-6yz+3xz\right)\)

A. Solid State Drive (SSD) 

B. Hard Disk Drive (HDD) 

C. USB Flash Drive

a) \(461+\left(x-45\right)=387\)

\(x-45=387-461\)

\(x-45=-74\)

\(x=-74+45\)

\(x=-29\)

b) \(11-\left(-53+x\right)=97\)

\(11+\left(53-x\right)=97\)

\(53-x=97-11\)

\(53-x=86\)

\(x=53-86\)

\(x=-33\)

c) \(-\left(x+84\right)+213=-16\)

\(-\left(x+84\right)=-16-213\)

\(-\left(x+84\right)=-229\)

\(x+84=229\)

\(x=229-84\)

\(x=145\)

Does the nurse take your temperature in the morning?

1. impressive

2. friendliness

3. instructions

4. compulsory

5. separate

\(\dfrac{1}{2}+\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}\)

\(=\dfrac{1}{1\times2}+\dfrac{1}{2\times3}+\dfrac{1}{3\times4}+\dfrac{1}{4\times5}+\dfrac{1}{5\times6}\)

\(=1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{6}\)

\(=1-\dfrac{1}{6}\)

\(=\dfrac{5}{6}\)

a) \(\left(2^2\right)^3.\dfrac{1}{2^5}.4^3\)

\(=\left(2^2\right)^3.\dfrac{1}{2^5}.\left(2^2\right)^3\)

\(=\left(2^2\right)^3.\left(2^2\right)^3.\dfrac{1}{2^5}\)

\(=\left(2^2\right)^6.\dfrac{1}{2^5}\)

\(=2^{12}.\dfrac{1}{2^5}\)

\(=\dfrac{2^{12}}{2^5}\)

\(=2^7\)

\(=128\)

b) \(\left(5^3\right)^4.\dfrac{1}{5^3}.125:5^4\)

\(=\left(5^3\right)^4.\dfrac{1}{5^3}.5^3:5^4\)

\(=\left(5^3\right)^4.\dfrac{5^3}{5^3}:5^4\)

\(=\left(5^4\right)^3:5^4\)

\(=\left(5^4\right)^2\)

\(=5^8\)