1. The numerator and denominator of the fraction are multiplied or divided by the same number at the same time (except 0), and the unit of the fraction remains unchanged. …………………………………………………………(×)

Because: the decimal unit is variable, such as three quarters, and multiplied by seven at the same time, it becomes twenty-eight and twenty-one, and the decimal unit changes.

57 out of 76 are the simplest fraction ............................................................ (x).

Because: 76-57 and 19 are common factors, you can continue to subtract points.

2. The fraction after adding 1 is 1, and the fraction after subtracting 2 is 3/4. What is the score?

A: Yes 12+0 1.

Multiplying the denominator of three-quarters numerator by three at the same time equals 65438+9/02, and adding three equals 1 1 1 plus 1 equal to12, which can be roughly divided into

3. A fraction is 3/4 after the numerator adds 1; After the molecule subtracts 1, its value is 1.

Ask for this score?

A: Five eighths.

3/4 numerator denominator multiplied by 2 at the same time equals 6/8, which can be divided into about 3/4; Subtracting 1 equals five eighths, and subtracting 1 from five eighths equals four eighths, which can be roughly divided into two halves of 1.