① When x = - 3, the value of the algebraic expression ax to the 5th power BX to the 3rd power + cx-6 is 17, then when x = 3, the value of the algebraic expression is () ② Li Ming used a square with a side length of a, a square with a side length of B, and two rectangles with length and width of B and a to make a big square. He found a mathematical rule by comparing the total area before and after the puzzle Please express the mathematical law discovered by Li Ming with mathematical formula and use the above law to calculate the square of (2x + 3Y)

① When x = - 3, the value of the algebraic expression ax to the 5th power BX to the 3rd power + cx-6 is 17, then when x = 3, the value of the algebraic expression is () ② Li Ming used a square with a side length of a, a square with a side length of B, and two rectangles with length and width of B and a to make a big square. He found a mathematical rule by comparing the total area before and after the puzzle Please express the mathematical law discovered by Li Ming with mathematical formula and use the above law to calculate the square of (2x + 3Y)

-(17+6)-6=-29
(a+b)^2=a^2+b^2+2*ab
(2x+3y)^2=(2x)^2+(3y)^2+2*2x*3y=4x^2+12xy+9y^2

Solution equation: 2 (x + 15) = 2-3 (X-7)
2x+30=2-3x+21,①
5x=-7 ②
x=-7/5 ③
Please answer the following questions:
(1) The basis for obtaining formula (1) is___________________ ；
(2) The basis for obtaining formula 2 is___________________ ；
(3) The basis for obtaining formula 3 is___________________ .

Solution equation: 2 (x + 15) = 2-3 (X-7)
2x+30=2-3x+21,①
5x=-7 ②
x=-7/5 ③
Please answer the following questions:
(1) The basis of formula (1) is: the law of multiplicative distribution;
(2) The basis for obtaining formula 2 is: to move items and merge similar items;
(3) The basis of formula 3 is: one factor = product △ another factor

1 ÷ (1-75%) 200 × (1 + 20%) 75% × 5 / 7 × 4 / 3, 0.8 × 99 + 0.8

1÷(1-75%)
=1÷25%
=4
200×（1＋20％）
=200x1.2
=240
75% × 5 / 7 × 4 / 3
=3/4x4/3x5/7
=1x5/7
=5/7
0.8×99＋0.8
=0.8x(99+1)
=0.8x100
=80

Let ∑ BN be absolutely convergent, and (1) the sequence an is bounded; (2) Lim an exists; (3) the ∑ an converges. It is proved that if there is one of the above three conditions
Then ∑ anbn is absolutely convergent

It is proved that (1) holds and ∑ anbn is absolutely convergent
Then (2) (3) can push out (1)

If a ≠ 0, find the value of 3A + 3B + B / A + CD / 2

AB is opposite to each other, CB is reciprocal to each other
Then: a + B = 0; a / b = - 1; CD = 1
3a+3b+b/a+cd/2
=3(a+b)+b/a+cd/2
=0-1+1/2
=-1/2

Given that the obtuse angle α satisfies sin α = Cos2 α, how much is tan α equal to

sinα=1-2sin^2α ==> sinα=1/2
α=150°,tanα=-√3/3

(- 3x to the 4th power, y to the 2nd power) divided by (- 2x / 3 to the nth power, y to the 2nd power) = - MX to the 8th power, y to the 2nd power

(- 3x ^ 4Y ^ 2) ^ 2 ^ (- 2 / 3x ^ NY ^ 2) = - MX ^ 8y ^ 29x ^ 8y ^ 4 ^ (- 2 / 3x ^ NY ^ 2) = - MX ^ 8y ^ 29 ^ (- 2 / 3) * x ^ (8-N) y ^ (4-2) = - MX ^ 8y ^ 29 * (- 3 / 2) * x ^ (8-N) y ^ (4-2) = - MX ^ 8y ^ 2-27 / 2 * x ^ (8-N) y ^ 2 = - MX ^ 8y ^ 2m = - 27 / 28-n = 8N = 0, so m = - 27 / 2, n = 0

What is diag used to calculate in linear algebra? Is diag used to calculate similar diagonal matrix?

Diag is the abbreviation of diagonal matrix
For example, diag (1,2,3) is a matrix
1 0 0
0 2 0
0 0 3

The intersection coordinates of line 3x + y-6 = 0 and circle x ^ 2 + y ^ 2-2y-4 = 0 are

The equation of circle is reduced to x ^ 2 + (Y-1) ^ 2 = 5
It can be seen from the straight line that y = - 3x + 6
By substituting the above formula into the equation x ^ 2 + (- 3x + 6-1) ^ 2 = 5 of the circle, we get
x^2-3x+2=0
x1=1 x2=2
Then substitute the line to find the ordinate Y1 = 3, y2 = 0
So the intersection points are (1,3) and (2,0)

Given that x is an integer and (2 / x + 3) + (2 / 3-x) + (2x + 18 / X & # 178; - 9) is an integer, find the sum of all the values of X that meet the conditions

2/(x+3)+2/(3-x)+(2x+18)/(x²-9)
=2/(x+3)-2/(x-3)+(2x+18)/(x²-9)
=[2(x-3)-2(x+3)+(2x+18)]/(x²-9)
=(2x+6)/[(x+3)(x-3)]
=2 / (x-3) is a positive number,
And X is a positive number
Ψ x-3 = 2 or x-3 = - 2 or X-2 = 1, or x-3 = - 1
∴x=5,1,3,2
The sum of all the values of X is
5+1+3+2=11