Rút gọn các phân số sau thành phân số tối giản:

a)  − 270 450

b)  11 − 143

c)  − 26 − 156

Mark the letter A, B, C, or D on your answer sheet to indicate the underlined part that needs correction in each of the following questions.

The detailed study of fossils, rather like a crime investigation, it involves the piecing together of many diverse fragments of evidence.

A. the piecing

B. it

C. detailed study

D. of many diverse

Tìm các số tự nhiên n sao cho các phân số sau có giá trị là số nguyên

a)  A = n + 4 n

b)  B = n − 2 4

Rút gọn các phân số sau

a)  7.6 − 7.4 7.3

b)  7 9.10 2 − 2.10 2

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

I'm sure Luisa was very disappointed when she failed the exam.

A. Luisa must be very disappointed when she failed the exam.

B. Luisa must have been very disappointed when she failed the exam.

C. Luisa may be very disappointed when she failed the exam.

D. Luisa could have been very disappointed when she failed the exam.