x= 3/20

4/30

a: \(\frac{-2x+3}{5xy}+\frac{3x-4}{5xy}\)

\(=\frac{-2x+3+3x-4}{5xy}=\frac{x-1}{5xy}\)

b: \(\frac{x\left(x-2\right)}{x-3}+\frac{3}{3-x}\)

\(=\frac{x^2-2x-3}{x-3}\)

\(=\frac{\left(x-3\right)\left(x+1\right)}{x-3}=x+1\)

c: \(\frac{2x+7}{3\left(x+2\right)}-\frac{x+5}{3\left(x+2\right)}\)

\(=\frac{2x+7-x-5}{3\left(x+2\right)}\)

\(=\frac{x+2}{3\left(x+2\right)}=\frac13\)

d: \(\frac{5}{2x+6}+\frac{3}{x^2-9}\)

\(=\frac{5}{2\left(x+3\right)}+\frac{3}{\left(x-3\right)\left(x+3\right)}\)

\(=\frac{5\left(x-3\right)+6}{2\left(x-3\right)\left(x+3\right)}=\frac{5x-9}{2\left(x-3\right)\left(x+3\right)}\)

e: \(\frac{3x}{x+2}+\frac{x+3}{x^2-4}\)

\(=\frac{3x\left(x-2\right)+x+3}{\left(x-2\right)\left(x+2\right)}=\frac{3x^2-6x+x+3}{\left(x-2\right)\left(x+2\right)}\)

\(=\frac{3x^2-5x+3}{\left(x-2\right)\left(x+2\right)}\)

f: \(\frac{3x+2}{\left(x+2\right)^2}-\frac{1}{x+2}\)

\(=\frac{3x+2-\left(x+2\right)}{\left(x+2\right)^2}=\frac{2x}{\left(x+2\right)^2}\)

12,12 x 7,5 + 12,12 : 2 + 12,12 + 12,12

= 12,12 x 7,5 + 12,12 x 0,5 + 12,12 x 1 + 12,12 x 1

= 12,12 x (7,5 + 0,5 + 1 + 1)

= 12,12 x 10

= 121,2

121,2 nha bạn

Lời giải:
Ta có:

$10\equiv -1\pmod {11}$

$\Rightarrow 10^{2022}\equiv (-1)^{2022}\equiv 1\pmod {11}$

$\Rightarrow A=10^{2022}-1\equiv 1-1\equiv 0\pmod {11}$

Vậy $A\vdots 11$

ok

A= 10^2022-1

Ta có thể thấy 10^2022=100000000...........0000000000 

 10000000.......0000000000-1 thì lúc nnày tổng bằng

9999999999999999........................999999999999999999999

mà 99999999999999999999999....................9999999999999999999chia hết cho 11 nên tổng này chia hết cho 11

Giúp mình với ạ 

Mn ơi 

XIX 

Năm 1879 thuộc thế kỉ 19