Phần ảo của số phức z = 5 + 2i bằng

A. 5  

B. 5i  

C. 2   

D. 2i

Read the following passage carefully, and then select the best option A, B, C or D to complete it

Technology, general term for the processes by (1) _______ human beings fashion tools and machines to increase (2) _______ control and understanding of the material (3) _______. The term is derived from the Greek words tekhnē, which refers to an art or craft, and logia, (4) _______ an area of study; thus, technology means, literally, the study, or science, of crafting.

Many historians of science argue not only that technology is an essential condition of advanced, industrial civilization (5) _______ also that the rate of technological change has developed its (6) _______ momentum in recent centuries. Innovations now (7) _______ to appear at a rate that increases geometrically, (8) _______ respect to geographical limits or political systems. These innovations tend to transform traditional cultural (9) _______, frequently with unexpected social consequences. Thus technology can be conceived as both a creative and a destructive (10) _______.

Question 9:

A. systems

B. networks

C. world

D. matters

Cho hàm số y = x + 2 x 2 + 1  có đồ thị (C). Mệnh đề nào dưới đây đúng?

A. (C) cắt trục hoành tại ba điểm. 

B. (C)cắt trục hoành tại hai điểm.

C. (C)cắt trục hoành tại một điểm. 

D. (C)không cắt trục hoành

Cho đa thức M = abc(ab + bc + ca) + (a + b + c) - 1.

a) Phân tích đa thức M thành nhân tử nếu c = 1.

b) Phân tích đa thức M thành nhân tử.

tai x = may vay