Analysis: This question examines the application of linear equations with one variable. According to the topic, if Xiaohong does the X way correctly, she will do it wrong (20-x). According to the conditions, the equations can be listed to get the answer.

The problem solving process is as follows:

Solution: Let Xiaohong do the right X way.

5x-(20-x)÷2×2=64

5x-(20-x)=64÷2×2

5x-20+x=64

6x=64+20

6x=84

x= 14

A: You got it right: 14.

Extended data:

Properties of division operation

1. If a number is divided by (or multiplied by) a number and then multiplied by (or divided by) the same number, the number remains the same.

2. A number divided by the product of several numbers can be divided by the factors in the product in turn.

3. The quotient of a number divided by two numbers is equal to the number divided by the dividend in the quotient, and then multiplied by the divisor in the quotient.

If the product of several numbers is divided by a number, any factor in the product can be divided by this number and then multiplied by other factors.

When the sum of several numbers is divided by a number, you can divide each addend by this number first, and then add each quotient.

6. If the difference between two numbers is divided by a number, the quotient obtained by dividing the minuend by this number can be subtracted from the quotient obtained by dividing the minuend by this number.