(1) How to express the formula that the second power of 7-5 equals 8 times 3. N The first is the second power of 7 - the second power of 5 is equal to 8 times 3. The second is the second power of 9 - the second power of 7 is equal to 8x4

(1) How to express the formula that the second power of 7-5 equals 8 times 3. N The first is the second power of 7 - the second power of 5 is equal to 8 times 3. The second is the second power of 9 - the second power of 7 is equal to 8x4

Item n: (2n + 5) ^ 2 - (2n + 3) ^ 2 = 8 * (n + 2) n = 1.2.3

How about the formula (6 + 4) multiplied by 3 divided by 2?

(6 + 4) multiply 3 by 2
=10 divided by 2 times 3
=Five times three
=15

3.4-6.10 use the formula of addition and multiplication to work out that the answer is equal to 24

There are four
3×[10+4+(-6)]=24
3×(10-4)-(-6)=24
10-4-3×(-6)=24
4-(-6)×10÷3=24

Simple calculation of 5 / 7 × 16 × 21 / 5

5/7*16*21/5=5/7*21/5*16=3*16=48

a. What triangle is B and C with three sides and (A2-B2) (c2-a2-b2) = 0
a. B and C are triangles with three sides and (A2-B2) (c2-a2-b2) = 0. What kind of triangle is it? Can it be said that it is an isosceles right triangle

(a²-b²)(c²-a²-b²)=0
A & # 178; = B & # 178; or C & # 178; = A & # 178; + B & # 178;
A = B or C & # 178; = A & # 178; + B & # 178;
A triangle is an isosceles triangle or a right triangle

62 -- 63 = 1 move only one number to make the equation hold (the sign cannot be moved)

I've read this question, so I know the answer. Move 6 and put it in the upper right corner of 2, which is the sixth power of 2, and the equation holds

Let a be a square matrix of order n over the number field F, a ^ 3-6a ^ 2 + 11a-6i = 0, and try to determine the range of k such that ki + A is an invertible matrix
F is a general number field

But what field is f? Different fields should have different ranges of K?
The condition is (A-I) (a-2i) (a-3i) = 0
That is, at least one of det (A-I), DET (a-2i), DET (a-3i) is 0
So K ≠ - 1, - 2, - 3
Furthermore, (A-I) (a-2i) (a-3i) is the Annihilation Polynomial of a, so it
It is a multiple of the minimum polynomial, but the minimum polynomial is related to the characteristic multinomial
So the characteristic polynomial of a cannot have division 1,2,
When k ≠ - 1, - 2, - 3, DET (KI + a) is not 0,
Ki + A is reversible
So the range is {K | K ∈ F and K ≠ - 1, - 2, - 3}

There is a two digit number, the number on the one digit is a, and the number on the ten digit is B. if the two digit number is transposed with the number on the ten digit, the two digit number obtained is larger than the original two digit number, which one is bigger?

According to the meaning of the title, 10b + a < 10A + B, so 9b < 9a, so B < A, that is a > B

Let a be a square matrix of order 3, a * be the adjoint matrix of a, and a ^ (- 1) be the inverse matrix of A. if determinant a = 4, find the value of determinant (1 / 2 ^ t) ^ (- 1) - (3a ^ *) ^ t
Also find determinant (1 / 2a) ^ *

Using the following adjoint matrix and determinant properties to derive
A*=|A|A^{-1}
(kA)*=k^{n-1}A*
(A^T)*=(A*)^T
(A^T)^{-1}=(A^{-1})^T
|kA|=k^n|A|
|A^T|=|A|
（kA）^{-1}=k^{-1}A^{-1}

A number of 18 times less than 48 21, find this number

Let this number be X
18X+21=48
18X=27
X=27/18
X=1.5