\(202^2-54^2+256.352\)

\(=\left(202-54\right)\left(202+54\right)+256.352\)

\(=\left(202-54\right).256+256.352\)

\(=256\left(202-54+352\right)=256.300=76800\)

\(202^2-54^2+256.352\)

\(\Leftrightarrow\left(202-54\right).\left(202+54\right)+256.352\)

\(\Leftrightarrow\left(202-54\right).256+256.352\)

\(\Leftrightarrow256.\left(202-54+352\right)=128000\)

a) 542 x 7 + 542 x 2 + 542

= 542 x 7 + 542 x 2 + 542 x 1

= 542 x (7 + 2 + 1)

= 542 x 10

= 5420

b) (126 x 35 + 157 x 55) x (132 - 6 x 22)

= (126 x 35 + 157 x 55) x (132 - 132)

= (126 x 35 + 157 x 55) x 0 (Số bất kỳ nào nhân với 0 vẫn = 0)

= 0

c) 897 x 99 + 897

= 897 x 99 + 897 x 1

= 897 x (99 + 1)

= 897 x 100

= 89700

a) \(542.7+542.2+542\)

\(=542.\left(2+7+1\right)\)

\(=542.10=5420\)

b) \(\left(126.35+157.55\right).\left(132-6.22\right)\)

\(=13045.0=0\)

c) \(897.99+897\)

\(=897.\left(99+1\right)\)

\(=897.100=89700\)

`2022+2022:1/3+2022+2022:1/5`

`=2022+2022xx3+2022+2022xx5`

`=2022xx(1+3+1+5)`

`=2022xx10=20220`

20220

`->2022+2022×3+2022+2022×5`

`->`\( 2022 × ( 1 + 3 + 1 + 5 )\)

`->2022xx10`

`->20220`

36396

`2022 : 0,25  + 2022 : 0,1 -  2022 : 0,5 + 2022 : 1/6`

`=2022 xx 4 +2022 xx 10 - 2022 xx 2 + 2022 xx 6`

`= 2022 xx(4+10-2+6)`

`=2022 xx 18`

`=36396`

36396

=2022x100=202200

= 2022 x ( 57 + 42 + 1 )

= 2022 x 100

= 202200

\(2022\times57+2022\times42+2022=2022\times\left(57+42+1\right)=2022\times\left(57+43\right)=2022\times100=202200.\)

A=2022(1/1-1/2+1/2-1/3+...+1/2021-1/2022)

  =2022(1/1-1/2022)

 =2022.2021/2022

ket qua tu tinh nha

A = \(\dfrac{2022}{1.2}+\dfrac{2022}{2.3}+\dfrac{2022}{3.4}+...+\dfrac{2022}{2021.2022}\)

= \(\dfrac{2022}{1}-\dfrac{2022}{2}+\dfrac{2022}{2}-\dfrac{2022}{3}+\dfrac{2022}{3}-\dfrac{2022}{4}+...+\dfrac{2022}{2021}-\dfrac{2022}{2022}\)

= \(\dfrac{2022}{1}-\dfrac{2022}{2022}\)

= \(2021\)

Chúc bạn học tốt!! ^^

2022.( 1/1.2+ 1/2.3+...+ 1/2021+2022)

2022. ( 1-1/2+1/2-1/3+......+1/2021-1/2022)

2022.( 1-1/2022)

2022.2021/2022

2021

2022x(2023-155)-2023x(2022-155)

=2022x2023-2022x155-2023x2022+2023x155

=(2022x2023-2023x2022)+(2023x155-2022x155)

=0+155x(2023-2022)

=155x1=155