In a subtraction equation, the sum of the subtracted number and the difference is 20 and what is the

The subtracted number is: 10.

The process is as follows:

1) Known condition: the subtracted number, the sum of the subtraction and the difference is 20, which can be expressed as: the subtracted number + the subtraction + the difference = 20.

2) The relationship between the subtracted number, the subtracted number, and the difference: the subtracted number = the subtraction + the difference. Available: subtraction + difference = subtraction.

3) Subtracted + minus + difference = 20, substituting the minus + difference = subtracted can be obtained: subtracted + subtracted = 20. Get minus = 20 2 = 10.

Extended Material: Evolution of Subtraction Equations.

Subtracted = minus + poor. Minus = Minus - Difference. Difference = subtracted - subtracted.

Variable substitution is a very effective method to solve problems, especially when dealing with some complex inequality problems. Reasonable substitution can often simplify the information of the problem, highlight the implicit conditions, and communicate the relationship between quantity and quantity, which plays an important role in discovering the problem-solving ideas and optimizing the problem-solving process.

Commonly used variable substitutions mainly include partial substitution, global substitution, triangular substitution, and fractional substitution.

Solution: It is known that in a subtraction equation, the subtracted number + the subtracted number + difference = 20, and the subtracted number - the subtracted number = the difference, the subtracted number = the subtracted number + the difference obtained the subtracted number + the subtracted number = 20

2 subtracted = 20

Minus = 20 2

Subtracted = 10

Answer: The subtracted number is 10

In a subtraction equation, the sum of the subtraction and the difference is 20, and the subtraction is as follows:

The minus here is: 10. Logical thinking for problem solving.

Yes: Let's first find the difference + subtraction = subtraction, and change the subtraction + subtraction + difference = 20 to the subtraction + subtraction = 20, so as to find the value of the subtraction. So according to the question, there are subtraction + subtraction + difference = 20, subtraction + subtraction = 20, 2 subtraction = 20, so subtraction = 10.

As a problem, it is a simple equivalent substitution problem, which examines the application of "difference + subtraction = subtraction". The students' ability to solve problems flexibly was tested, and they were proficient in equivalent substitution and could solve problems.

Mathematical Equivalent Substitution:

Definition of equivalent substitution: the substitution of one quantity (or part of a shedding quantity) for another spike (or part of another quantity) that is equal to it.

"Equal substitution" refers to the substitution of a quantity with a quantity equal to it, it is a basic method of thought in mathematics, and it is also the basis of the algebraic method of thinking, and the narrow idea of equal substitution is reflected by the nature of the equation is the transitivity of the equation: if a=b, b=c, then a=c.

The subtracted number is: 10.

1) Known condition: subtracted number, subtraction refers to the sum of the number and the difference is 20, which can be expressed as: subtracted number + subtraction + difference = 20.

2) From the relationship between the subtracted, the subtracted, and the difference: the subtracted = subtracted + the difference, it can be obtained: the subtraction + the difference = the subtracted number.

3) Subtraction + subtraction + difference = 20, substituting the subtraction + difference = subtraction can be obtained: subtraction + subtraction = 20, get the subtraction = 20 2 = 10.

The law of addition

When using the "truncation method" in addition or subtraction, add or subtract directly from the left high position (while paying attention to whether the next digit needs to be carried or misplaced) until you get the answer that the option requires precision.

When using the "truncation method" in multiplication or division, in order to make the results as accurate as possible, it is necessary to pay attention to the direction of the interception approximation:

1. To expand (or shrink) one multiplier factor, it is necessary to shrink (or expand) another multiplier factor.

2. Enlargement (or shrinkage of the small) dividend.

You need to expand (or shrink) the divisor. If you are looking for the sum or difference of the products of two times (i.e., a*b+ -c*d).

3. If you touch the side of the plus sign to expand (or shrink), you need to shrink (or expand) the other side of the plus sign.

4. Enlarge (or reduce) one side of the minus sign, then enlarge (or reduce) the other side of the minus sign.

The subtracted number is: 10.

The process is as follows:

1) Known condition: the subtracted number, the sum of the subtraction and the difference is 20, which can be expressed as: the subtracted number + the subtraction + the difference = 20.

2) The relationship between the subtracted number, the subductive liquid, and the difference: the subtracted number = the subtraction + the difference. Available: subtraction + difference = subtraction.

3) Subtracted + minus + difference = 20, substituting the minus + difference = subtracted can be obtained: subtracted + subtracted = 20. Get minus = 20 2 = 10.

Subtraction formula

1. Minus - minus = difference.

2. Difference + subtraction = subtraction.

3. Minus - difference = minus.

Subtraction-related properties.

1. Anti-exchange rate: subtraction is anti-exchange, if a and b are any two numbers, then (a-b)=-b-a). Yu Meng.

2. Anti-coupling law of vertical buried bridges.

Subtraction is anti-conjunctive, and when trying to redefine subtraction, then a-b-c=a-(b+c).

Subtracted = minus + poor.

Therefore, the minus of the empty silver + difference = the subtracted = 220

Then, let the banquet be reduced by the number of congratulations + minus + difference = 220 + 220 = 440

Because the subtraction = subtraction + difference, the subtraction + subtraction + difference = the subtraction + the reduction = 220 2 = 440.

Solution: It is well known that in a deduction formula for segment fibrillation, 34 minus the difference in the defeat of the clasp grip, the difference is, the difference is negative, the difference is minus, the difference is subtracted, the difference is 342 (negative zero difference) = 342 (negative minus minus).

Subtracted = minus + poor.

Subtracted + Subtractive + Difference = Subtracted x2 = 440

Subtracted + Subtracted + Difference = 20

Subtracted = Subtracted + Difference = 20 2 = 10

The subtracted number is: 10.

Let the subtracted number, Lakai virtual subtraction, Sun jujube, and difference be the rotation of the burn x,y,zx-y=z, respectively, so x-y-z=0 is derived

Their sum is x+y+z=

The sum of the two formulas.

2x=so x=