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A circular paperboard, 25.12 cm circumference, 1 cm radius, circular paperboard area
25.12 ／ 3.14 ／ 2 = 4 (CM), 3.14 × (42-12), = 3.14 × (16-1), = 3.14 × 15, = 47.1 (cm2). Answer: the area of circular paperboard is 47.1 cm2
If the fourth power of | m + 5 | and (n-2) are opposite to each other, then the power of M is n=
Why two nonnegative numbers
The opposite number indicates that the sum of the two numbers equals 0
The absolute value must be greater than or equal to 0, and the even power of a number must be greater than or equal to 0
The sum of two positive numbers cannot be zero
So m + 5 can only be 0, M = - 5
n-2=0,n=2
So the second power of (- 5) is 25
Given that m and N are opposite numbers and satisfy (M + n) ^ 2 - (n + 4) ^ 2 = 16, find the value of m ^ 2 + n ^ 2-2mn
Wrong type of T, T. it is known that m and N are opposite to each other, and satisfy (M + 4) ^ 2 - (n + 4) ^ 2 = 16. Find the value of m ^ 2 + n ^ 2-2mn
Because m and N are opposite numbers
So m + n = 0
So (M + 4) ^ 2 - (n + 4) ^ 2 = 16,
（m+4+n+4)(m+4-n-4)=16
(m+n+8)(m-n)=16
8（m-n）=16
m-n=2
So m ^ 2 + n ^ 2-2mn = (m-n) ^ 2 = 4
Given that m and N are opposite numbers and satisfy (M + 4) 2 - (n + 4) 2 = 16, the value of M 2 + N 2 − Mn is obtained
∵ m and N are opposite numbers, that is, M + n = 0 ①, ∵ (M + 4) 2 - (n + 4) 2 = [(M + 4) + (n + 4)] [(M + 4) - (n + 4)] = (M + n + 8) (m-n) = 16, ∵ 8 (m-n) = 16, i.e., M-N = 2 ②, the simultaneous solution of ① and ② is m = 1, n = - 1, then M2 + N2 Mn = 1 + 1 + 1 = 3
Given that m and N are opposite numbers and satisfy (M + 4) (M + 4) - (n + 4) (n + 4) = 16, find the value of mm + nn-n / m
(m+4)²-(n+4)²=16
(m+4+n+4)(m+4-n-4)=16
m. N is opposite to each other, that is, M + n = 0
8*(2m)=16
m=1
n=-1
m²+n²-n/m=1+1+1/1=3
Decomposition factor M & # 178; - N & # 178; + 2 (m-n)
m²-n²+2(m-n)
=(m+n)(m-n)+2(m-n)
=(m-n)(m+n+2)
If you don't understand, I wish you a happy study!
(M + n) & # 178; - 2 (M + n) (m-n) + (m-n) & # 178; factorization
Solution
Consider m + N and M-N as a whole
simple form
=[(m+n)-(m-n)]²
=(m+n-m+n)²
=(2n)²
=4n²
The remaining factors after extracting the common factors are the same as a: 3M & sup2; N + 6MN & sup2; and 2m & sup2; N + 4Mn & sup2; + Mn B: a&
C: 6X & sup3; + 4x & sup2; + 2x and 6x & sup2; y + 4xy + 2Y
A: 3m2n + 6mn2 = 3MN (M + 2n) and 2m2n + 4mn2 + Mn = Mn (2m + 4N + 1) B: a&
C: 6x3 + 4x2 + 2x = 2x (the square of 3x + 2x + 1) and 6x2y + 4xy + 2Y = 2Y (the square of 3x + 2x + 1)
Option C
The 180cm person stands 2 meters in front of the plane mirror. How high is its image in the mirror?
There are additional questions, the best answers, how many meters is the distance between people and images? If he walks 0.2 meters towards money, what is the distance between people and images?
The image in the mirror is higher than the original object, so it is 180cm
It's twice 4m apart
After walking 0.2 meters, it's like 0.2m. It's 0.4 in all
4M-0.4
=3.6
A 75 meter man stands 2 meters in front of a plane mirror. How high is his image in the mirror and how to calculate it?
Don't answer if you're not good at math
Same height, 1.75 M
Explanation - plane mirror imaging law: the object in the plane mirror into a virtual image, the same size as the object, the same distance from the image and object to the mirror
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