Giải bất phương trình:

\(\dfrac{x+2}{89}+\dfrac{x+5}{86}>\dfrac{x+8}{83}+\dfrac{x+11}{80}\)

Chứng minh:

\(\dfrac{x-x^2+1}{x-x^2-1}< 1\)

Chứng minh bất đẳng thức:

\(a^2+ab+b^2\ge0\)

\(\dfrac{x+6}{x-5}+\dfrac{x-5}{x+6}=\dfrac{2x^2+23x+61}{x^2=x-30}\)

Giải phương trình:

a) \(\dfrac{x+2}{x+1}+\dfrac{3}{x-2}=\dfrac{3}{x^2-x-2}+1\)

Thực hiện phép tính:

\(\dfrac{1}{x\left(x+y\right)}+\dfrac{1}{y\left(x+y\right)}+\dfrac{1}{x\left(x-y\right)}+\dfrac{1}{y\left(y-x\right)}\)

Nếu  a ⋮ m và  b ⋮ m thì

A.  a + b : m

B.  a - b : m

C.  a - b ⋮ m

D.  a - b   k h ô n g   ⋮   m

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

  Cooperation is the common endeavor of two or more people to perform a task or reach a jointly cherished goal. Like competition and conflict, there are different forms of cooperation, based on group organization and attitudes.

  In the first form, known as primary cooperation, group and individual fuse. The group contains nearly all of each individual’s life. The rewards of the group’s work are shared with each member. There is an interlocking identity of individual, group and task performed. Means and goals become one, for cooperation itself is valued. 

  While primary cooperation is most often characteristic of preliterature societies, secondary cooperation is characteristic of many modem societies. In secondary cooperation, individuals devote only part of their lives to the group. Cooperation itself is not a value. Most members of the group feel loyalty, but the welfare of the group is not the first consideration. Members perform tasks so that they can separately enjoy the fruits of their cooperation in the form of salary, prestige, or power. Business offices and professional athletic teams are examples of secondary cooperation.

          In the third type, called tertiary cooperation or accommodation, latent conflict underlies the shared work. The attitudes of the cooperating parties are purely opportunistic: the organization is loose and fragile. Accommodation involves common means to achieve antagonistic goals: it breaks down when the common means cease to aid each party in reaching its goals. This is not, strictly speaking, cooperation at all, and hence the somewhat contradictory term antagonistic cooperation is sometimes used for this relationship.

Which of the following is an example of the third form of cooperation as it is defined in the fourth paragraph?

A. Members of a farming community share work and the food that they grow

B. Two rival political parties temporarily work together to defeat a third party

C. Students form a study group so that all of them can improve their grades

D. A new business attempts to take customers away from an established company

Mark the letter A, B, C, or D on your answer sheet to indicate the most suitable response to complete each of the following exchanges.

Amy: "Do you have a minute?" - David: "_____________." 

A. Well, that makes sense

B. Yes, but please be brief

C. That's just great. Thanks.

D. Sorry, I left my watch home