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If the sum of the two numbers is 18 and one of them is represented by the letter X, then the product of the two numbers is expressed algebraically as A.18x B.x(18+x) C.x(x-18) D.x(18-x)
Answer d one number is x, the other number is 18-x
If the sum of two numbers is 100 and one of them is represented by the letter A, then the algebraic expression for the product of a and the other is_____ . multiple choice questions
A.a（100+a）
B.a（a-100)
C.100a
D.a（100-a）
D
Algebraic evaluation
(several ^ several represents the power of several)
1. If A.B.C are all rational numbers, and a + B + C = 0, a ^ 3 + B ^ 3 + C ^ 3 = 0, find the algebraic formula A ^ 5 + B ^ 5 + C ^ 5 =?
2. A / (a ^ 2 + A + 1) = 1 / 6, find the value of the algebraic formula A ^ 2 / (a ^ 4 + A ^ 2 + 1)
3. A.b.c.d is an unequal integer, ABCD = 25, find a + B + C + D
4. X / (a-b) = Y / (B-C) = Z / (C-A), find x + y + Z
5. X + y = 1, find x ^ 3 + y ^ 3 + 3xy
6. A ^ 2 + B ^ 2 = C ^ 2 = AB + BC + AC, a = 1, find (a + B-C) ^ 2004
7. A = 2003x + 2004, B = 2003x = 2003, C = 2003x = 2005, find a ^ 2 + B ^ 2 + C ^ 2-ab-bc-ac
I still don't understand the first and second questions
As shown in the picture. The writing is not good
If 1 + 2 + 3 + +N = m, find (AB ^ n) × (a ^ 2B ^ n-1) × The value of × (a ^ n-1b ^ 2) × (a ^ NB)
So simple? Remove the brackets, add the same base index, and merge the same base
（ab^n)×(a^2b^n-1)×… ×(a^n-1b^2)×(a^nb)
=a^(1+2+...+n)*b^(n+n-1+...+1)
=a^m*b^m.
2 / (M + n) + 3 / (m-n) = 3 / 2,1 / (M + n) - 9 / (m-n) = - 1, find the value of M, n
2/（m+n）+3/（m-n）=3/2,①
1/（m+n）-9/（m-n）=-1②
Let 1 / (M + n) = a, 1 / (m-n) = B
2a+3b=3/2③
a-9b=-1④
③ X 3 + 4
7a=7/2
a=1/2
b=(a+1)/9=1/6
therefore
m+n=2
m-n=6
m=(2+6)÷2=4
n=2-4=-2
Lesson 7 on page 10
Dalai supermarket, Xinhua Bookstore and fashion shop are located in an east-west street. Dalai supermarket is 50m to the west of Xinhua Bookstore, and fashion shop is 80m to the east of Xinhua bookstore. Xiaoming walks eastward from Xinhua Bookstore for 30m, and then eastward for - 40m. Question: which direction is Xiaoming in Dalai supermarket? How many meters is the distance?
In the direction of the fashion shop? How many meters apart?
You've learned the number axis. At this time, Xiaoming is 40 meters east of Dalai supermarket, 90 meters west of fashion shop, and 10 meters west of Xinhua bookstore
A company has 12 and 6 machines in warehouse A and B respectively. Now it needs to transfer 10 machines to county a and 8 machines to county B. It is known that the freight for transporting a machine from warehouse A to county a is 40 yuan, the freight for transporting a machine from warehouse A to county B is 80 yuan, the freight for transporting a machine from warehouse B to county a is 30 yuan, and the freight for transporting a machine from warehouse B to county B is 50 yuan He design to complete the task, so that the total freight just 940 yuan
Let X of the 10 machines in a county come from B warehouse, the meaning of the question is: 30x + 40 (10-x) + 50 (6-x) + 80 (2 + x) = 940, and the solution is: x = 4. Therefore, in order to complete the scheduling task and the total freight is exactly 940 yuan, the design scheme is: transfer 4 machines from B warehouse to a county, 6-4 = 2 machines to B County; transfer 10-4 = 6 machines from a warehouse to a county, 8-2 = 6 machines to B county
Can I get back to you by six?
It took one minute for the train to get on the bridge and completely cross the bridge. The time for the whole train to be completely on the bridge is 40 s. The known bridge length is 1500 m,
I don't know, 1 minute = 60 seconds, that 40 seconds can be ignored
Divide time by distance = speed v
1500÷60=25
That's the speed of the train
Us [S] s 25 [M] m
Don't know, right
No, don't scold me
The fifth question on 21 pages of mathematics evaluation in grade one of junior high school
Title:
In hexagon ABCDEF, all angles are equal
(1) Find the degree of an internal angle
(2) Extend EF, AB and CD to two sides respectively, and intersect at points g, h and P. explore the characteristics of △ GHP and explain the reasons
(3) Judge the position relation of the opposite side of hexagon ABCDEF and explain the reason
PS: (2) and (3) should have the process of ∵, and should be written vertically
Because my level is not enough, I can't put up the hexagon. I'm sorry
1.180-360 / 6 = 120 (the sum of external angles of polygon is 360 degrees)
2 in triangle GAF, the angle GAF and GFA are 360 / 6 = 60
So the angle G is 180-60-60 = 60
Similarly, the angles h and P are all 60 degrees
So the triangle GHP is an equilateral triangle
3 parallel and equal
What is the meaning of the title of a kind of operation in mathematics of grade one
That is to say, it specifies a new operation. When you meet the symbol of the new operation, you should change it into the meaning of the new operation it provides
If a & B = 2Ab, then 2 & 3 & 4 = 2 * 2 * 3 & 4 = 12 & 4 = 2 * 12 * 4 = 96
RELATED INFORMATIONS
- 1. The answer to the evaluation of algebraic formula in the dialing training of the seventh grade mathematics volume I
- 2. Algebraic evaluation exercises When A-B / A + B = 3, find the value of algebraic formula 2 (a-b) / (a + b) - 4 (a + b) / 3 (a-b)
- 3. If a + B + C = 0, simplify: (a + b) to the third power + (B + C) to the third power + (B + C) to the third power + (a to the third power + B to the third power + C to the third power) Yes, three times
- 4. 1. The absolute value of m plus 2 plus the square of N + 3 equals 0. What is the value of M and N? 2. (m-1) multiply x to the power of m by Y is a binomial about X, y, and find M 3. The absolute value power of M + 1 of polynomial x multiplied by Y square + m multiplied by x square + 1 is a cubic trinomial about X 2、 two m (m-1)x y 3、 |m+1| 2 2 X y +mx +1 And the first question. Can't square be zero?
- 5. In triangle ABC, given (a ^ 2-C ^ 2) ^ 2 = B ^ 2 (2C ^ 2-B ^ 2), find the size of angle C
- 6. If C is an integer, try to judge the shape of △ ABC
- 7. |The square of ab-2 | + (B-1) = 0, find 1 / AB + 1 / (a + 1) (B + 1) + 1 / (a + 2) (B + 2) +... + 1 / (a + 2010) (B + 2010)
- 8. Given x = √ 5 + 2, then the square of the algebraic formula x-4x + 3 is
- 9. The algebraic expression (m-n) 2 can be interpreted as______ ．
- 10. Given a + B = 2, ab = 3, find 1A ^ 3b of 2 + A ^ 2B ^ 2 + 1ab ^ 3 of 2
- 11. It is known that monomials only contain the letter X, and their exponents are 3 and 2 respectively. When x = 2 and y = 3, their values are 24, write this algebraic formula
- 12. In the algebraic expression 3x, 3 is called the sum of the letter factor X___ The coefficient of 1 / 2Ab is___ .
- 13. It is known that there are only letters X and Y in the monomial, and their exponents are 3 and 2 respectively. When x = 2 and y = 3, its value is equal to 24. Try to write this algebraic formula
- 14. Given that the value of algebraic formula (x-a) 2 + B is always positive, then the value of B should be () A. Negative number B. non negative number C. non positive number D. positive number
- 15. Please write an algebraic expression containing X. no matter what rational number x takes, the value of the algebraic expression is always non negative
- 16. When Xiao Fang calculates a + bc-a ^ 2 / A ^ 2 + B ^ 2 + C ^ 2 (a, B, C are not equal to each other), he finds that if a and B are exchanged, the value of this formula remains unchanged, If a + B + C = 1, the constant value a + (bc-a ^ 2 / A ^ 2 + B ^ 2 + C ^ 2) bc-a ^ 2 is a molecule
- 17. Given that 1 / 4 + 5 (x-1 / 2004) = 1 / 2, find the value of algebraic formula 3 + 20 (x-1 / 2004)
- 18. Factorization (xsquare-xsquare) - (xsquare-x) - 2
- 19. 204x out of 3 minus 8x out of 3 equals 200
- 20. The square of 100 pie minus r equals 200