-Factorization of X (x-y-8) + y (y-x-8) + 8 (8-x + y)

Primitive = - X & # 178; + XY + 8x + Y & # 178; - xy-8y + 64-8x + 8y
=-x²+y²+64
This obviously can't be broken down

Factorization if (x ^ + y ^) ^ - 8 (x ^ + y ^) - 9, then x ^ + y ^^=
Although it is to fill in the blanks, but hope to give me a process

Is it (x ^ + y ^) - 8 (x ^ + y ^) - 9 = 0?
Let a = x ^ + y^
Then a ^ - 8A - 9 = 0
(a-9)(a+1)=0
a=9,a=-1
The square is greater than or equal to 0
So a = x ^ + y ^ > = 0
So a = - 1 doesn't hold
So x ^ + y ^ = 9

Factorization x ^ 3-1 / 8 (y ^ 3)
What's the best way?

This is the application of the formula A ^ 3-B ^ 3 = (a-b) (a ^ 2 + B ^ 2 + AB), x ^ 3-1 / 8y ^ 3 = (x-1 / 2Y) (x ^ 2 + 1 / 4Y ^ 2 + XY) = 1 / 8 (2x-y) (4x ^ 2 + y ^ 2 + 4xy)

Five students from a, B, C, D and e participated in a program. Fortunately, they got one more beautiful gift. The thing is like this: there are two strings of gifts hanging on the wall, and only one can be taken from the bottom of one string at a time until the gift is finished. A gets the gift first, and then B, C, D and e get the second to fifth gifts. Of course, there are all kinds of ways, Then there are several different ways? After they open these gifts, they compare them carefully and find that gift D is the most beautiful. Who is the most likely to get gift D?

4 + 3 + 2 + 1 = 10 species

How do you feel after reading the article "smile penetrating the soul"

It's actually very brave for a child to face death with a smile. I think that smile contains her thanks to the people who saved her. What's more, she believes that someone will come to save her. Although she failed, she knows that everyone present has worked hard. Now the only thing she can do is to cheer everyone up and save others with a smile

What are human teachers besides dragonflies

The old horse knows the way, the ant

Solving equation 1 / 4x + 3 / 20 = 3 / 3
So, 1 / 4x + 3 / 20 = 3 / 5

1/4x=3/5-3/20
1/4x=12/20-3/20
1/4x=9/20
x=9/20*4
x=9/5

Simple calculation of 4.73 + 2.99

4.73+2.99
=4.73+3-0.01
=7.73-0.01
=7.72

Given the distance from point P to all points on ⊙ o, the maximum distance is 8, and the minimum distance is 2, what is the radius length of ⊙ o?
Please explain why

1. When p is inside the circle, the diameter of ⊙ o is the sum of the maximum distance and the minimum distance, that is, the diameter is 8 + 2 = 10, then the radius is 5.2; when p is outside the circle, the diameter is the difference between the maximum distance and the minimum distance, that is, the diameter is 8-2 = 6, then the radius is 3.2

After two successive price cuts of 20%, the current price is 64% of the original price

If the original price is x, if x is reduced by 20%, it will be 0.8x, and if x is 0.8 × 100%, it will be 64%

-Factorization of X (x-y-8) + y (y-x-8) + 8 (8-x + y)