In practical problems, how to know whether to use the least common multiple or the greatest common factor to solve the problem

In practical problems, how to know whether to use the least common multiple or the greatest common factor to solve the problem

If there is "at least" in the title, it is the least common multiple, and "at most" is the greatest common factor
The solution of the greatest common factor and the least common multiple
Greatest common factor
Decomposing quality factor method: decomposing several numbers into quality factor form and multiplying the common factor to get the greatest common factor
Find (12,18)
12=2×2×3
18=2×3×3
（12,18）=2×3=6
The solution of the least common multiple
Common methods for finding the least common multiple of several numbers are as follows:
(1) To find the least common multiple of several numbers, first check whether these numbers have a common divisor (not necessarily the common divisor of all known numbers, but the common divisor of any two numbers). If there are any, use their common divisor to divide continuously until every two numbers are coprime numbers, and then multiply all divisors and the final quotient, The product is the least common multiple of these numbers
Example: ① find the least common multiple of 12 and 18
2 and 3 are coprime, except so far
The least common multiple of 12 and 18 is 2 × 3 × 2 × 3 = 36
② Finding the least common multiple of 12, 18 and 24
1. Every two numbers of 2 and 3 are coprime numbers, except so far
12. The least common multiple of 18 and 24 is 2 × 3 × 2 × 1 × 3 × 2 = 72
To find the least common multiple of two numbers, we can use the relationship between the two numbers and their greatest common divisor and least common multiple
The relation is: the greatest common divisor × the least common multiple = the product of multiplication of two numbers
Example: find the least common multiple of 12 and 18
Because the greatest common divisor of 12 and 18 is 6 and the product of the two numbers is 12 × 18 = 216, the least common multiple of 12 and 18 is 216 △ 6 = 36
(3) Direct observation
① The relationship between two numbers is multiple
If the larger number is a multiple of the smaller number, then the larger number is the least common multiple of the two numbers. For example: 96 is a multiple of 16, 96 is the least common multiple of 96 and 16
② The two numbers are coprime
If two numbers are coprime numbers, then the least common multiple of the two numbers is the product of the two numbers. For example, the least common multiple of 7 and 13 is 7 × 13 = 91
Use inverse division
The question is too simple to answer
Find all complex numbers Z satisfying the following conditions at the same time, (2) the real part and imaginary part of Z are integers
Z = K + J.I, K is an integer, j is an integer
1+i
S or es should be added to the plural of zoo?
S
Given Z1 + Z2 = 3-5i, Z1 conjugate complex - Z2 conjugate complex = - 2 + 3I, find Z1 ^ 2-z2 ^ 2
z1^2-z2^2=(z1+z2)(z1-z2)
=Conjugate complex of (z1-z2) + (z1 + Z2)
=（-2+3i)(3+5i)
=-21- i
The answer is - 21 + I help to see what's wrong
It should be (3-5i) (- 2-3i)
In English, the phonetic sign of gloves and its correct pronunciation, V is followed by the plural number plus s, V is to read V or F? If there is a phonetic sign, it is better!
I remember that the teacher seemed to have said it before, but I forgot. Who knows the correct one, please let me know,
S / es pronunciation rules:
Read [S] after clear consonants; read [Z] after voiced consonants and vowels; read [iz] after [S] [F] [Z] / T ∫ / [Dr], so you should read [VZ]
I hope it will help you
The conjugate complex of complex z = 1 + I1 − I (where I is an imaginary unit) is equal to______ .
∵ complex z = 1 + I1 − I = (1 + I) 2 (1 − I) (1 + I) = 2I2 = I, ∵. Z = - I, so the answer is: - I
Is the plural of hero plus s or es?
ditto
Because it ends with O
Therefore, for, heroes
heroes
Live, plus
Plural: Heroes
If Z + Z1 = 4, Z * Z1 = 8, then Z / Z1=
What is the plural of hero
Because hero is a hero; hero, the meaning of hero, belongs to living, so the plural number is added with es. by the way, for words ending with O, as long as it means living, the plural number is added with ES; if there is no life, the plural number is added with s directly, In addition to this, there are several common: potato tomato Negro
Hero is living, so the plural number is added with es.
Heroes
heroes
Question supplement: I'm so dizzy. Which is right, hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero hero
Heroes is right. For those who end with O, add es. For those who end with O, add s.
heroes
The living plural ending with o has to be followed by es, so it's heroes
Not all living words ending in "O" have to add "es". For example, the plural of "Hippo" is "hippos", so it depends on remembering.
heroes