Significant number and approximate number If (a + 1) square + | b-2005 | = 0, then the b-th order of 2006-a=

Significant number and approximate number If (a + 1) square + | b-2005 | = 0, then the b-th order of 2006-a=

There are four significant digits
Because (a + 1) square + | b-2005 | = 0
Then the square of (a + 1) = 0
Ib-2005I=0
So a = - 1, B = 2005
It's the 2005 power of 2006 - (- 1)
=2006-(-1)
=2007

Write the set of natural numbers whose single digit is 3 by descriptive method
RT, I don't mean T-T

The set of natural numbers whose single digit is 3 can be expressed as {x | x = 10N + 3, n ∈ n}

N is a natural number, 2n is a natural number______ Number, 2n + 1______ Count

From the meaning of even number and odd number, we can know: if n represents natural number, then 2n is even number and 2n + 1 is odd number; so the answer is even and odd

The elements of set M are natural numbers and satisfy the following conditions: if x belongs to m, then 8-x belongs to M. how many sets m satisfy the condition of question setting?
Write out all sets m with two elements

0 = 0, get 0

The elements in the set M are non-zero natural numbers and satisfy x ∈ m, 8-x ∈ M
1. Write a set m with only one element
2. Write all sets m with 2 elements

1、{4}
2、{1,7}{2,6}{3,5}{4,4}

Are natural numbers and positive integers the same concept? What's the difference between N and N *?

Natural numbers include positive integers and 0
N is a natural number and N * is a positive integer

The difference between natural number N and positive integer n * n +

N is like 0.1.2.3.4.5 N * has no 0, such as 1.2.3.4.5

If the root 17-n is a natural number, then the value of positive integer n is

If the root 17-n is a natural number, the natural number 0

Which has more elements, positive integer set or natural number set?
They are all sets of infinite numbers, but the set of natural numbers has all the elements in the set of positive integers

There must be many sets of natural numbers. N * is a subset of n

Is the set of natural numbers equal to the set of positive integers

Definition of positive integer: except 0, all natural numbers are positive integers. In the set, we can use "n * or N +" to represent the number of objects. 1,2,3,4,5 ··· is called positive integer
So natural number set = positive integer + 0
So it's not equal to