Tìm x, biết:

a)  − 2 3 x + 1 5 = 3 10

b)  − 1 2   + 1 3 : x = 1

Chứng minh: 1 q − 1 q + 1 = 1 q ( q + 1 ) . Áp dụng để tính nhanh biểu thức sau:  N = 1 q ( q + 1 ) + 1 ( q + 1 ) ( q + 2 ) + . .. + 1 ( q + 5 ) ( q + 6 ) , với các mẫu thỏa mãn x ≠ 0 .

Mark the letter A, B, C or D on your answer sheet to indicate the sentence that best combines each pair of sentences in the following questions.

William Clark was not granted the rank of captain. Captain Lewis more or less ignored this and treated Clark as his equal in authority and rank.

A. William Clark was not granted the rank of captain because Captain Lewis more or less ignored this and treated Clark as his equal in authority and rank.

B. William Clark was not granted the rank of captain, thus Captain Lewis more or less ignored this and treated Clark as his equal in authority and rank.

C. Although William Clark was not granted the rank of captain, Captain Lewis more or less Ignored this and treated Clark as his equal in authority and rank.

D. As William Clark was not granted the rank of captain, Captain Lewis more or less ignored this and treated Clark as his equal in authority and rank.

Tính giá trị của biểu thức

a) M = x 2  - 8x + 7 tại x = 49;

b) N =  x 4  - 2 x 3  +  x 2  tại x = 10;

c) P = m 6   -   2 m 4 - m + m 2   +   m 3  biết m 3  - m + 2 = 0.

Phân tích đa thức thành nhân tử:

a) x 2  - 10x + 9;                         b) 2 x 2  - 5x + 2;

c) 3 x 2  - 10xy + 3 y 2 ;                  d) 2xy -  x 2  + 3 y 2  - 4y + 1;

g) 4x¹⁶ + 81;                             e) 8 x 2  - 12xy + 4 y 2  - 2x - 1;

h) 625 t 9  + 75 t 3  + 9;

i) ( 5   -   y ) 6  - 2(125 - 75y + 15 y 2  -  y 3 ) +1;

k)  x 4  + 2018 x 2  + 2017x + 2018.

Phân tích các đa thức sau thành nhân tử:

a) 5 x 2  – l0x y 2  + 5 y 4 ;                  b) x 4 2 - 2 x 2 ;

c) 49 ( y   -   4 ) 2  - 9 ( y   +   2 ) 2 ;            d) ( a ²   + b ² -   5 ) 2 -   2 ( ab   +   2 ) 2 .