(1 / 5 + x) △ 4 = 3

(1 / 5 + x) △ 4 = 3

11 and 4 / 9

1/2{x-1/3【x-1/4(x-2/5)】-3/2}=x+3/4

1/2{x--1/3[x--1/4(x--2/5)]--3/2}=x+3/4
x--1/3[x--1/4(x--2/5)]--3/2=2x+3/2
3x--[x--1/4(x--2/5)]--9/2=6x+9/2
3x--x+1/4(x--2/5)--9/2=6x+9/2
1/4(x--2/5)=4x+9
x--2/5=16x+36
5x--2=80x+180
--75x=182
x=--182/75.

Given that x > y > Z, 1 / (X-Y) + 1 / (Y-Z) > n / (x-z) is constant, find n

Let X-Y = a, Y-Z = B, then x-z = a + B, the original proposition is equivalent to proving 1 / A + 1 / B-N / (a + b) > 0
(a^2+b^2+2ab-nab)/[ab(a+b)]>0
Obviously AB (a + b) > 0, then a ^ 2 + B ^ 2 + 2Ab nab > 0
(a-b)^2+4ab-nab>0
So n

The definite integral proves that the definite integral of ∫ DX / 1 + X ∧ 2 (x > 0) is equal in [x, 1] and [1,1 / x]

 
 
If you don't understand, please ask. If you can solve the problem, please click "select as satisfactory answer" below

What's the rule of 7, 19, 37?

The fourth, eighth and twelfth prime numbers
Or: an = 3N ^ 2 + 3N + 1
7 = 3*1^2+3*1+1
19=3*2^2+3*2+1
37=3*3^2+3*3+1

If a is used to represent a natural number, then the two natural numbers adjacent to a are______ And______ ．

A is a natural number, and the two natural numbers adjacent to a are A-1 and a + 1, so the answer is: A-1, a + 1

What are the numbers in positive integer / natural number / integer / rational number / real number set?

Positive integers: 1,2,3,4,5,6,7,8,9
Natural numbers: 0,1,2,3,4,5,6,7,8,9 (after 2004, 0 is also a natural number)
Integer: ,-5,-4,-3,-2,-1,0,1,2,3,4,5,……
Rational numbers: include integers, finite decimals and infinite cyclic decimals, that is, numbers that can be written as M / N (m, n are integers and N ≠ 0) are rational numbers
Real number: including integer, finite decimal and infinite decimal

Number reasoning first row 1; second row 1,1 third row 1,2,3 what is the fourth row

1
1 1
1 2 3
1 2 6 9
Starting from the second row, the first number is the sum of the first row, the second number is the sum of the existing numbers in the second row, and so on

Using mathematical induction to prove that the cubic sum of three continuous positive integers can be divisible by 9

When n = 1, 1 ^ 3 + 2 ^ 3 + 3 ^ 3 = 36 can be divided by 9. Suppose that when n = k, x ^ 3 + (x + 1) ^ 3 + (x + 2) ^ 3 can be divided by 9. If n = K + 1, (x + 1) ^ 3 + (x + 2) ^ 3 + (x + 3) ^ 3 = (x + 1) ^ 3 + (x + 2) ^ 3 + x ^ 3 + 9x ^ 2 + 27x + 27 = [x ^ 3 + (x + 1) ^ 3 + (x + 2) ^ 3] + 9 (x ^ 2 + 3x + 3)

What is the minus 3 root minus 216?

The third root minus 216 is - 6, and the third root minus 216 is 6