Is complex fraction complex fraction

Is complex fraction complex fraction

A fraction contains fractions in its numerator or denominator, or both. Such fractions are called complex fractions
When at least one of the numerator and denominator of a fraction B is a fraction, a fraction B is called a complex fraction
In fact, there are differences in essence
Thank you^_ ^I wish you progress in your studies

Solving complex fraction
one
___ +1
（1+x^2)
___________________
one
___ -1
（1+x）^2
I don't have any points, so please do me a favor~

Change 1 into a fraction with the same denominator, that is, 1 = (1 + x ^ 2) / (1 + x ^ 2) = (1 + x) ^ 2 / (1 + x) ^ 2
Upper half = 1 / (1 + x ^ 2) + (1 + x ^ 2) / (1 + x ^ 2) = (1 + 1 + x ^ 2) / (1 + x ^ 2)
Lower half = 1 / (1 + x) ^ 2 - (1 + x) ^ 2 / (1 + x) ^ 2 = [1 - (1 + x) ^ 2] / (1 + x) ^ 2
Top half / bottom half = reciprocal of top half × bottom half, that is [(1 + 1 + x ^ 2) / (1 + x ^ 2)] × [(1 + x) ^ 2 / 1 - (1 + x) ^ 2]
That is [(2 + x ^ 2) × (1 + x) ^ 2] / (1 + x ^ 2) × [1 - (1 + x) ^ 2]=
After that is the addition, subtraction, multiplication and division of the unary equation!

The problem of complex fraction
One third divided by 5, that is, 1 / 3 / 5, must be equal to 1 / 15. But why is this wrong: the reciprocal of 1 / 3 / 5 = 3 / 5 is equal to 5 / 3?

Count the top first, then the bottom
Thank you!

Simplification of complex fraction
I don't know how to learn this
For example:
one
——
two
——
three
——
4　　　　　　　　　　　　　　　
It seems that according to the method can not calculate 1 / 24 of the answer

From the top, is the fraction line from long to short or from short to long? If it is from short to long, the answer is indeed 1 / 24. The molecule of the total molecule (1 / 2) / 3 is 1 / 2, and the denominator is 3. Multiply 2 up and down to get 1 / 6. The original formula is (1 / 6) / 4, and multiply 6 up and down to get 1 / 24. If it is from long to short, the answer is 3 / 8

What is the simplest centimeter of the square-3x + 1 / 2 and the Square-1 / 1 of the fractions x

x²-3x+2=(x-1)(x-2)
x²-1=(x+1)(x-1)
The simplest common denominator of the square-3x + 1 / 2 of fraction X and the Square-1 / 1 of fraction x is (x + 1) (x-1) (X-2)

If the value of the letter X in the fraction X / y is increased by 2 times and the value of Y is increased by 4 times, then the value of the fraction is expanded or reduced, and expanded or reduced by several times
It's x out of Y

2 times larger

The last two digits of a natural number are 72. The sum of all numbers is 72. It can also be divided by 72 to find the smallest one in such a natural number

If the last two digits are removed, the sum of all digits is 63, and xxxxxx00 can be divided by 100 at least, then as long as xxxxx can be divided by 18, so xxxxx is an even number
So the answer is 19999872

A four digit number minus the sum of its digits is 19 () 6. Do you know what the number in () is?

Let the original four digit number be ABCD, then ABCD = 1000A + 100b + 10C + D ABCD - (a + B + C + D) = (1000A + 100b + 10C + D) - (a + B + C + D) = 999a + 99b + 9C = 9 × (111a + 11b + C) --- is a multiple of 9, so this number can be divisible by 9, that is, 1 + 9 + () + 6 = 16 + () can be divisible by 9, so () can only be 2

A three digit number. The number on each digit is the same. The sum of each digit is 27. This number is (

999

Print out all Narcissus numbers. (a three digit number whose cubic sum of each digit is equal to the number itself)

153 370 371 407