The complete pairs of pronunciation and Glyph of the following words are () Jin avoids depression, Pian shares Europe's obsession, Miao threats, Xiang admires Xiansheng

The complete pairs of pronunciation and Glyph of the following words are () Jin avoids depression, Pian shares Europe's obsession, Miao threats, Xiang admires Xiansheng

What are the two phonetic symbols of C?

/S / and / K/

What are the two pronunciations of Pao?

Pao four sound, such as: bubble; soak
Pao, such as: bean curd bubble son; eye bubble son

What's 4 out of 13 times 3 out of 8

3/26

Find mathematical expressions
Sn=1/2+2/2^2+3/2^3+4/2^4+…… n/2^n
Find SN

1^2+2^2+3^2+.+n^2=n(n+1)(2n+1)/6
Proof method 1
n^2=n(n+1)-n
1^2+2^2+3^2+.+n^2
=1*2-1+2*3-2+.+n(n+1)-n
=1*2+2*3+...+n(n+1)-(1+2+...+n)
Because n (n + 1) = [n (n + 1) (n + 2) - (n-1) n (n + 1)] / 3
So 1 * 2 + 2 * 3 +... + n (n + 1)
=[1*2*3-0+2*3*4-1*2*3+.+n(n+1)(n+2)-(n-1)n(n+1)]/3
[front and back elimination]
=[n(n+1)(n+2)]/3
So 1 ^ 2 + 2 ^ 2 + 3 ^ 2 +. + n ^ 2
=[n(n+1)(n+2)]/3-[n(n+1)]/2
=n(n+1)[(n+2)/3-1/2]
=n(n+1)[(2n+1)/6]
=n(n+1)(2n+1)/6
Syndrome method 2
Using the formula of cubic difference
n^3-(n-1)^3
=1*[n^2+(n-1)^2+n(n-1)]
=n^2+(n-1)^2+n^2-n
=2*n^2+(n-1)^2-n
2^3-1^3=2*2^2+1^2-2
3^3-2^3=2*3^2+2^2-3
4^3-3^3=2*4^2+3^2-4
.
n^3-(n-1)^3=2*n^2+(n-1)^2-n
Add all the equations
n^3-1^3=2*(2^2+3^2+...+n^2)+[1^2+2^2+...+(n-1)^2]-(2+3+4+...+n)
n^3-1=2*(1^2+2^2+3^2+...+n^2)-2+[1^2+2^2+...+(n-1)^2+n^2]-n^2-(2+3+4+...+n)
n^3-1=3*(1^2+2^2+3^2+...+n^2)-2-n^2-(1+2+3+...+n)+1
n^3-1=3(1^2+2^2+...+n^2)-1-n^2-n(n+1)/2
3(1^2+2^2+...+n^2)
=n^3+n^2+n(n+1)/2
=(n/2)(2n^2+2n+n+1)
=(n/2)(n+1)(2n+1)
1^2+2^2+3^2+...+n^2=n(n+1)(2n+1)/6

14 × (- 11) of 39 and 15
How much is this problem equal to? How can it be easily calculated

-439 and 4 / 15
Simple operation:
(1 / 40-15) x (- 11)
=[40x (- 11)] - [1 / 15 x (- 11)]
=- 440 + 11 / 15
=- 439 and 4 / 15
Nearly 20 years have not done a math problem, I hope not wrong!

In the equation 3x ay = 8, if x = 3Y = 1 is one of its solutions, then the value of a is______ ．

Substituting x = 3Y = 1 into the equation 3x ay = 8, 9-A = 8 and a = 1 are obtained

Can 36 be divided by 0

No

Solve the equation 4x-25% x = 18.75

(4-25%)x=18.75
3.75x=18.75
x=18.75÷3.75
x=5

Use the square difference formula to calculate: ① 40 and 1 / 3 × 39 and 2 / 3 ② 2014 & # 178; - 2015 × 293 ③ 9 (10 + 1) (10 & # 178; + 1) + 1
The square difference formula is used to calculate:
① 40 1 / 3 × 39 2 / 3
②2014²－2015×293
③9﹙10＋1﹚﹙10²＋1﹚＋1
④5﹙a－2b﹚﹙1/5a＋2/5b﹚
⑤﹙﹣3a＋b﹚﹙﹣2b＋3a﹚＋4b²
⑥﹙x＋y﹚²－﹙x－y﹚²
⑦25²－24²
⑧﹙1-1/2²﹚﹙1－1/3²﹚﹙1－1/4²﹚...﹙1－1/9²﹚﹙1－1/10²﹚
⑨ If (a + b) &# 178; = 16, (a-b) &# 178; = 8, find the value of ab
⑩ Calculation: (- a-2b) (2a-b) - (a-2b) (B + 2a)
⑾﹙a＋2b﹚﹙a－2b﹚＋﹙a＋2b﹚²－4ab
⑿﹙2x＋y＋1﹚﹙2x＋y－1﹚
⒀﹙x－2y﹚﹙x＋2y﹚－﹙x+2y﹚²
⒁﹙a＋b＋c﹚²
⒂﹙2x－y－1﹚²