Let a be a third-order matrix, and its determinant | a | = 5. Find the value of the determinant | (5a *) - 1 |

Let a be a third-order matrix, and its determinant | a | = 5. Find the value of the determinant | (5a *) - 1 |

|Is that the meaning
= 1/ |5A*|
= 1/ (5^3 |A|^2)
= 1/5^5

Suppose that the determinant of the third-order matrix A = (α, β, γ) is equal to a, find the determinant of the matrix C = (α - β, β + 2, γ, α + β - γ)

Note matrix B=
1 0 1
-1 1 1
0 2 -1
So AB = C
detC=detAdetB

What is four plus minus eleven minus one divided by three

I don't know what kind you want
One is: [4 + (- 11) - 1] / (- 3) = (8 / 3), that is, 8 / 3
The other is: [4 + (- 11)] - 1 / (- 3) = 22 / 3, which is negative seven and one third
Hope to be useful to you!

How much is the surface area of the original cuboid
Hurry

It's not right. Let's find the edge length of cube first
The average square is 25 square centimeters. Then the edge length is 5 centimeters
The height of the cuboid is 7 cm. The bottom of the cuboid is a square, and its area is the same as that of the cuboid, which is 25 square cm
So the surface area of the cuboid is: 50 + 140 = 190 square centimeters

Given that the greatest common divisor of a and B is 6, and that a times b equals 126, what is a + B?

Given that the greatest common divisor of a and B is 6, then both a and B should be integral multiples of 6,
A times B should be an integral multiple of 6 * 6 = 36;
126 is not an integer multiple of 36, so this problem is wrong

In the first 1000 natural numbers, how many can be divided by 2 but not by 3 or 5

1-1000 medium
1000 / 2 = 500 are divisible by 2
There are 1 000 / 6 = 166 divisible by 2 and 3
1000 / 10 = 100 are divisible by 2 and 5
1000 / 30 = 33 are divisible by 2, 3 and 5
So 500-166-100 + 33 = 267

Calculation of 616 / 36 * 18 / 88 with simple method

Divide X by 1 / x, using the commutative law of multiplication = 18 / 36 * 616 / 88 = 0.5 * 616 / 88 = 308 / 88
About 4, = 77 / 22 = 7 / 2

It is necessary to simplify ((a2-3a) / (a2-6a + 9)) / ((a2-5a) / (a2-11a + 30)). Note: A2 is the square of A

1、 In the first step (a2-5a) can be changed into a (a-5) four. (a2-11a + 30) can be changed from cross multiplication to (a-5) * (a-6)

What is a negative number plus a positive number? What is a negative number plus a negative number,

A negative number plus a positive number equals a negative number or a positive number or 0. For example, - 2 + 1 = - 1, - 2 + 4 = 2, - 2 + 2 = 0
A negative number plus a negative number equals a negative number

Solving the system of linear equations with three variables {3x + y + 2Z = 2x + y + 3Z = 11 x-y-4z = - 10

3x+y+2z=2 ……… (1)2x+y+3z=11……… (2)x-y-4z=-10 ……… (3)(2)+(3) 3x-z=1……… (4)(1)-(2) x-z=-9……… (5) (4) - (5) 2x = 10, x = 5, substituting x = 5 into (5) 5-Z = - 9z = 14, substituting x = 5, z = 14 into (3) 5-y-4 *