Do negative numbers belong to natural numbers?

Do negative numbers belong to natural numbers?

The natural numbers are: 0,1,2,3,4,5,6
Negative numbers, of course, don't belong

Can natural numbers be negative

No

What are the three letters

A. Three pictures, a, one picture. B, two pictures, B, one picture. C, one picture, C, one picture. D, two pictures, D, one picture. E, three pictures, e, one picture. F, three pictures, F, two pictures. G, one picture. H, three pictures, h, one picture. I, three pictures, I, two pictures. J, two pictures, J, two pictures. K, two pictures, K, one picture. L, one picture. L, one picture. M, two pictures, m, one picture. N, three pictures, n, one picture. O, one

Three eighths plus x equals two fifths to solve the equation (process)

Two fifths minus three eighths

How to simplify the calculation of 88 * 125

88*125
=(80+8)*125
=80*125+8*125
=10000+1000
=11000

As shown in the figure, in △ ABC, ∠ BCA = 90 ° and ⊙ o with BC as diameter intersects AB at point P, q is the midpoint of AC. judge the position relationship between PQ and ⊙ O and explain the reason

The position relationship between PQ and ⊙ o is: tangent. The reasons are as follows: ① connect OP and CP. ∵ BC is the diameter, ∵ CP ⊥ AB, in RT △ APC, q is the midpoint of the hypotenuse AC; ∵ PQ = CQ = 12ac (the middle line of the hypotenuse of the right triangle is equal to half of the hypotenuse), ∵ QPC = ∵ QCP; op = OC, ∵ OPC = ∵ OCP, BCA = 90 degree, ∵ OPQ = 90 degree, ∵ op ⊥ PQ, Op = radius, ∵ P Q and ⊙ o are tangent to point P

The price of a drug is 11% lower than that in the past. How much is the current price? Thank you very much

The price of a drug is 11% lower than in the past, and the current price is 89% of the original price

Let the domain of function y = f (x) be [0,1], and find the domain of function y = f (x + a) + F (x-a)

The domain of F (x) is [0,1],
In F (x + a), 0 ≤ x + a ≤ 1, that is - a ≤ x ≤ 1-A,
In F (x-a), 0 ≤ x-a ≤ 1, that is, a ≤ x ≤ 1 + a,
The domain of definition of function y = f (x + a) + F (x-a) is the intersection of set {x | - a ≤ x ≤ 1-A} and {x | - a ≤ x ≤ 1 + a}
(1) When a > 1 / 2, 1-A

Design algorithm to find 1 ^ 2 + 2 ^ 2 + 3 ^ 3 + 4 ^ 2 + +The value of 99 ^ 2 + 100 ^ 2, where ^ 2 is the square, is the square of one plus the square of two plus the square of one hundred. How to design? The algorithm is not a block diagram. The second part of the first step is given,

The first step is to assign I = 1 and S = 0
The second step is to calculate s plus I ^ 2, which is still represented by S
The third step is to judge whether I is less than or equal to 100. If not, add 1 to I, still use I to represent, return to the second step; if not, output s, end the algorithm

The price of a commodity has been raised by a quarter and then reduced by a fifth. The present price is lower than the original ()

Consider the original price as unit 1
1 + 1 / 4 = 5 / 4 units after price increase
5 / 4 × (1-1 / 5) = 5 / 4 × 4 / 5 = 1
That is, the current price is 1:1 compared with the original price, which is equal
The price of a commodity is increased by a quarter and then decreased by a fifth. The present price is equal to the original price