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How many 5-digit numbers can 123456 be composed of
If it can be repeated, that is to say, we can consider that each person has six choices. A total of five choices are 6x6x6x6x6. If you can't: if you are in high school, you should know that the permutation combination 5A = 6x5x4x3x2 = 720 kinds of 6. If you are not in high school, you should take five numbers from them first, that is, there are six ways to get rid of one, and then the first of the five permutations has five
RELATED INFORMATIONS
- 1. Let the square of the process (the square root of 2 + 2) = a + B times the square root of 2, a + B= a. B is a rational number
- 2. If the equation x ^ 2 + MX + 1 = 0 of X has two unequal real roots, the value range of real number m is as follows: A. (- 1,1) B, (- 2,2) C, (negative infinity, - 2) ∪ (2, positive infinity) d, (negative infinity, - 1) ∪ (1, positive infinity)
- 3. How to solve equation 0.2 times 8 plus 0.4x equals 18?
- 4. Solution equation: 8x-2.8 = 40-x
- 5. There are four real numbers. The first three numbers form an equal ratio sequence, and their product is - 8. The last three numbers form an equal difference sequence, and their product is - 80
- 6. 123456 make up two three digit numbers. Each number can only be used once. What is the minimum difference between the two three digit numbers?
- 7. 9 times the square root of 10 ^ 4
- 8. If the equation 25 - | x + 1 | - 4 × 5 - | x + 1 | = m has real roots, then the value range of real number m is () A. m＜0B. m≥-4C. -4≤m＜0D. -3≤m＜0
- 9. How to check the equation 4x-18 times 2 = 20
- 10. The solution equation is: 1) X-1 of 2x-1 + 5x-8 of 1-2x = - 3 (2) 3-x of 1-x - 7-x of 5-x = 1 - X & # 178; - 8x + 7 of 7 x²-2
- 11. There are four real numbers. The product of the first three arithmetical sequences is 216, and the sum of the last three arithmetical sequences is 24
- 12. The solution equation: (40-0.8x) &# 178; + (30-0.5x) &# 178; = 16 & # 178;
- 13. 3x + 1 / 4 = 3 / 5 solution equation
- 14. It is known that the first three numbers of four positive real numbers are equal difference sequence, the last three numbers are equal ratio sequence, the sum of the first and the third is 8, and the product of the second and the fourth is 36 (II) if the first three numbers are the first three terms of the arithmetic sequence an and the last three numbers are the first three terms of the proportional sequence BN, let CN= an.bn To find the first n terms and TN of the sequence CN
- 15. There are four real numbers. The first three numbers form an equal ratio sequence, and their product is - 64. The last three numbers form an equal difference sequence, and their product is - 640 Find these four numbers, find the detailed process
- 16. There are four real numbers. The first three are in equal proportion sequence, and their product is 216. The last three are in equal difference sequence, and their sum is 12 Set up four unknowns!
- 17. Three unequal real numbers form an equal difference sequence, and then form an equal ratio sequence after proper exchange of positions, so as to find the common ratio of the equal ratio sequence
- 18. Three unequal real numbers form an arithmetic sequence. After properly exchanging the positions of the three numbers, they become an arithmetic sequence. Then the common ratio of the arithmetic sequence is___ ．
- 19. Three real numbers that are not equal to each other form an arithmetic sequence. If these three numbers are properly arranged, they can become an equal ratio sequence, and the sum of these three numbers is 6, then these three numbers can be calculated
- 20. The sequence {an} is an equal ratio sequence, m, N, P are equal difference sequence, if am = 4, an = 6, then the value of AP is equal