If the monomial - 2m6n and 5xm2xny are of the same kind, then x=______ ，y=______ ．

If the monomial - 2m6n and 5xm2xny are of the same kind, then x=______ ，y=______ ．

∵ the monomial - 2m6n and 5xm2xny are of the same kind, ∵ 2x = 6, y = 1, ∵ x = 3, y = 1

If (M + 1) 2x3yn-1 is a binomial of degree six with respect to X and y, then what condition ()
A. M is any number, n = 2B. M is any number, n = 4C. M ≠ - 1, n = 4D. M, n is any number

From the meaning of the question: 3 + (n-1) = 6, n = 4; m + 1 ≠ 0, m ≠ - 1, so choose C

It is known that the monomial (m-2) x ^ 3Y ^ n-3 is a quintic monomial with respect to the letters X and y, then M and N satisfy the condition that

(m-2) x ^ 3Y ^ (n-3) is a binomial of degree 5 about the letters x, y
The results are as follows:
3+(n-3)=5
m-2≠0
n=5
m≠2

a. B is any two rational numbers

c = (a + b) - (a - b) = 2 * b
b > 0 -> c > 0 -> a + b > a - b
b < 0 -> c < 0 -> a + b < a - b

There were 450 chickens and ducks in total. Later, half of the chickens were sold and 30 ducks were bought. At this time, the chickens were twice as many as the ducks. How many were there?
I'm writing about X for chickens and 450-x for ducks
X = 450-x + 30, x = 320, 130
But it's wrong to substitute half of the chicken = twice of duck + 30. I doubt the question is wrong, and I doubt several people. Besides, the simpler the formula, the better

If there are x chickens, there are (450-x) ducks. Because half of the chickens are sold and 30 ducks are bought, the equation x can be divided by 2 = 2 (450-x + 30), and the solution x is 384. So there are 384 chickens and 66 ducks. Believe me, it must be right!

Find the maximum and minimum value of the function y = (x ^ 4 + x ^ 2 + 5) / (x ^ 2 + 1) ^ 2

y=(x^4+x^2+5)/(x^4+2x^2+1)
=(x^4+2x^2+1-x^2+4)/(x^4+2x^2+1)
=1+(4-x^2)/(x^4+2x^2+1)
=1+(5-(x^2+1))/(x^2+1)^2
=1-1/(x^2+1)+5/(x^2+1)^2
Let t = 1 / (x ^ 2 + 1), 0

When m takes what value, the solution of the binary linear equations 2x + my = 4, x-2y = 0 of X, y is a positive integer

First, solve the binary linear equations, x = 2Y, y = 4 / (4 + m), because X and y are required to be positive integers. Therefore, according to y = 4 / (4 + m), M can go to 0 - 2 - 3 corresponding, y is 1 24, X is 2 48
That's the answer. Well, I forget that if I haven't learned negative numbers in the first day of junior high school, there is only one solution. M is 0. At this time, X is 2 and Y is 1

3.8.13.18.…… What is the general term formula of

If the first term is 3, then an = a1 + (n-1) d = 3 + (n-1) * 5 = 5n-2

In math class, the teacher and students calculated the volume of the earth by using the volume formula of the ball v = 4-3r, which is 9.05 × 10km,
In math class, the teacher and the students calculated the volume of the earth by using the volume formula of the ball v = 4.3r, and then the teacher asked, "the sun can also be regarded as a sphere, its radius is 10 times that of the earth, so how many cubic kilometers is the volume of the sun?" the students immediately calculated, and soon many students raised their hands to say that they had finished, and Xiao Ding's answer was 9.05 × 10km, Xiaoxin's answer is 9.05 × 10 ^ 15km, and Xiaoming's answer is 9.05 × 10 ^ 17km. Which of the three students has the right answer? Please write down the process,

The volume is proportional to the cube of the radius, so the radius becomes 100 times, and the volume should be 1000000 times. Therefore, Xiaoming's answer of 9.05 × 10 ^ 17km is correct
Hope to adopt

Mathematics of grade one in junior high school; practical problems and linear equation of one variable
If the purchase price of a product is reduced by 8% and the selling price remains unchanged, how much of the original profit is increased by 10 percentage points? If the purchase price of a product is reduced by 6.4%, the profit is increased by 8%, how much of the original profit rate of selling this kind of product is? If the purchase price of an electronic product is increased by 35%, and then the advertisement of 50 yuan rental fee for 10% discount is put out, the profit of each electronic product is still 208 yuan, How much is the purchase price of this product? The purchase price of a product is 100 yuan, and the price is 140 yuan. The profit margin is required to be at a discount of no less than 5%. How much is the minimum discount for selling this product,
It takes 14 days for Party A to do it alone, 18 days for Party B to do it alone, and 12 days for Party C to do it alone. Party A and Party B cooperate in the first seven days, but after Party B leaves for a period of time, the latter part is completed by Party B and Party C in two days. How many days does Party B leave? Party A and Party B contract a project. Party A and Party B complete it in 12 months and Party B complete it in 15 months. Now two pairs of buildings are built together and their efficiency is improved by 40%, How many months can the two teams build together?

1. Assume that the original price is x and the selling price is y
that
Y-(100%-8%)X=(100%+10%)(Y-X)
Y=180%X
So the original profit was 80%
2. Suppose the income is a and the cost is B, then the profit is C = a-b
Original profit rate = C / A
Now the cost is b *. 936
Make an equation based on the current 8% increase in profit margin
A-0.936B/A=(A-B)*1.08/A
144b = 0.08A
Original profit margin = A-B / a = 44.4%
3. Suppose the purchase price of this product is x yuan
【（1+35%）x】*90%-50=x+208
1.35X*0.9=X+208+50
X=1200
4. Set a discount of X
140x=100+5%*100
x=0.75
That's 7.50% off