b

Tính
e, \(E=\dfrac{4^6.3^4.9^5}{6^{12}}\)                                             f, \(F=\dfrac{2^{13}+2^5}{2^{10}+2^2}\)

g, \(G=\dfrac{21^2.14.125}{35^5.6}\)                                         h, \(H=\dfrac{45^3.20^4.18^2}{180^5}\)

1. I (study) have studied English for 5 years.
2. They (work) have worked here since 1975.
3. He has never (be) been there.
4. Mary (lose)loses her hat.
5. Listen ! somene (knock) is knocking at the door.
6. The earth (circle)circles the sun once every 365 days.
7. The farmers (work) are working in the field at the moment.
8. Rivers usually (flow) flow to the sea.
9. Look ! the cat (run) is running after the dog.
10. He always (talk) talks loudly in the library.

Tính
a, \(A=\dfrac{3^{10}.11+3^{10}.5}{3^9.2^4}\)                                    b, \(B=\dfrac{2^{10}.13+2^{10}.65}{2^8.104}\)

c, \(C=\dfrac{4^9.36+64^4}{16^4.100}\)                                      d, \(D=\dfrac{72^3.54^2}{108^4}\)

6. CMR: 
\(a,\) \(A=2+2^2+2^3+...+2^{2004}\) chia hết cho 3 và 15
\(b,\) \(B=1+3+3^2+...+3^{99}\) chia hết cho 40
\(c,\) \(C=5+5^2+5^3+...+^{2004}\) chia hết cho 6 và 31

CMR: 
a, 5⁵ - 5⁴ + 5³ ⋮ 7
b, 7⁶ + 7⁵ - 7⁴ ⋮ 11
c, 10⁹ + 10⁸ + 10⁷ ⋮ 222

Tìm chữ số tận cùng:

a, 2222³³³                                                         b, 32463³²³
c, 242¹⁰⁰                                                            d, 7¹⁹⁹⁹
e, 555575⁶⁹⁹⁰ . 25¹⁵⁰                                    g, 48¹⁹⁹²
h, 818¹⁰² - 262¹⁰²                                           i, 17⁵ + 24⁴ - 13²¹ 
k, 2 + 2² + 2³ + ... + 2¹⁰⁰                                  l, 9² . 9⁴ . 9⁶ . ... .9¹⁰⁰