CMR p/số \(\dfrac{n^3+2n}{n^4+3n^2+1}\) tối giản với n∈Z

Choose the best answer a, b, c or d
1. She lives ... 13 Le Loi street, Dong Hoi city
     A. on     B. in       C. at      D. under
2. What about ... to  music?
     A. listen      B. listened       C. listens          D. listening
3. Why don't you ... your homework?
     A. do     B. does       C. did         D. doing

CMR : phân số \(\dfrac{2n-3}{n-4}\)tối giản (n∈N;n≠4)

cho A=\(\dfrac{2}{11}\)+\(\dfrac{2}{13}\)+\(\dfrac{2}{15}\)+\(\dfrac{2}{17}\)+\(\dfrac{2}{19}\)+\(\dfrac{2}{21}\)+\(\dfrac{2}{23}\)+\(\dfrac{2}{25}\)+\(\dfrac{2}{27}\)+\(\dfrac{2}{29}\)

CMR:\(\dfrac{2}{3}\)<A<2

tìm x,y ∈ Z với y ≠ 0: \(\dfrac{x}{7}\)+\(\dfrac{1}{y}\)=\(\dfrac{-1}{14}\)

tính nhanh:

B=\(\dfrac{1}{18}\)+\(\dfrac{1}{54}\)+\(\dfrac{1}{108}\)+....+\(\dfrac{1}{990}\)

1. A. on                                  B. by                             C. with                              

2. A. roller coaster                  B. ride                           C. guided tour

3. A. surprised                        B.surprising                 C.bored                            

4. A. mane                              B. feather                      C.fur                                

5. A. will become                   B. be                            C. am becoming                

6. A. two days after               B. two days ago            C. last two days                

The reason...i phoned him was to invite him to a party
A.which               B.of which                   C.what                  D.for which