Why are these two equal, how did they come out, math?

First, the formula of the equal difference series is an a1+(n—1)d;

a5＝a1+4d，a6＝a1+5d，a7＝a1+6d；

So A5+A7 2A1+10D, which is exactly twice as much as A6.

The reason why these two are equal is because it is a series of equal differences.

The sum of the 11 terms, A6 is exactly the middle term, and the sum of the first term is 11 times that of A6. Suppose the term difference of the difference series is, a7=a6+b. Thus a5 + a7 = 2a6. Positive B and Negative B are just eliminated. The topic is very easy to understand.

an} is a series of equal differences, a5+a7=10, a6-a5=a7-a6, then 2a6=a5+a7=10,a6=(a5+a7) 2, let the tolerance be d, a1=a6-5d, a2=a6-4d, a3=a6-3d, a4=a6-2d, a5=a6-d, a7=a6+d, a8=a6+2d, a9=a6+3d, a10=a6+4d, a11=a6+5d, s11=a1+a2+... +a11=11a6=11×（a5+a7）/2=55

Because it's a series of equal differences.

A6 is exactly in the middle, so it is equal to the average of A5 and A7.

It is the nature of the equal difference series, the equal difference median term.

How to prove that two sets are equal in mathematics Let any x belong to set a, and then prove that x belongs to set b according to the conditions; In the same way, it is enough to let any y belong to the set b to prove that it also belongs to the set a, to put it bluntly, it is to prove by definition, and this abstract proof problem generally adopts definition or uses the anyway method....

They are equal!

The rationale is:

The law of calculation of the power of the square.

a＾m）＾n＝a＾mn。Hall of the Fierce Nucleus.

It can be obtained according to the rules above.

e y) x 2 Zhi Tease e (xy 2). Pretend.

The square difference formula a minus b the square of b.

a+b）(a-b)

<> the middle two steps are the principle, familiar and can be done in one step.

Divide by the negative power is equivalent to multiplying by the power of the power.

丨a丨 =a

According to the perfect square formula.

丨ab+ac丨 = (丨ab丨 +丨ac丨 +2abac).

Hello, here is the exact square formula that is derived.

Yes. Because.

a b squared [ b-a)] square b a squared.

Yes. (a-b) are the same.

a-b）²＝b-a）²＝a²-2ab+b²

So the result is the same, and the numbers in () can be opposite to each other, without affecting the result.

The equality of these two is conditional, not all the time. If you want to know when it is equal, you can solve this equation. Except for this solution, they are all not equal.

For general x, the equation does not always hold for a general x, unless it is true for a particular x.

For example, x=2, left=0, right≠0.

The logarithm given in the question is equal, and the specific process is shown in the figure below, which mainly uses the logarithmic base formula.

Hello! The question in this question is to ask why these two are equal.

Did it help you? Good luck with your learning.

After dividing the formula on the right, you can get the same as the one on the left, which is a very simple problem.