Ta có: \(B=\frac12+\frac13-\frac14+\frac15-\frac16+\cdots-\frac{1}{2022}+\frac{1}{2023}\)

=>\(B=\frac12+\frac13+\frac14+\frac15+\frac16+\cdots+\frac{1}{2022}+\frac{1}{2023}-2\left(\frac14+\frac16+\cdots+\frac{1}{2022}\right)\)

\(=\frac12+\frac13+\frac14+\frac15+\cdots+\frac{1}{2022}+\frac{1}{2023}-\frac12-\frac13-\cdots-\frac{1}{1011}\)

\(=\frac{1}{1012}+\frac{1}{1013}+\cdots+\frac{1}{2022}+\frac{1}{2023}\)

=C

=>B-C=0

`2022 \times 123 \times 12 - 2022 \times 11`

`= 2022 \times (123 \times 12 - 11)`

`= 2022 \times (1476 - 11)`

`= 2022 \times 1465`

`= 2962230`

\(2022\times2005-2000\times2022+15\times2022-20\times2021\)

\(=2022\times\left(2005-2000+15\right)-20\times2021\)

\(=2022\times20-20\times2021\)

\(=20\times\left(2022-2021\right)\)

\(=20\times1\)

\(=20\)

a, 2022 \(\times\) 2005 - 2000 \(\times\) 2022 + 15 \(\times\) 2022 - 20 \(\times\) 2021

= (2022  \(\times\) 2005 - 2000 \(\times\) 2022 + 15 \(\times\) 2022 )- 20 \(\times\) 2021

= 2022 \(\times\) (2005 - 2000 + 15) - 20  \(\times\) 2021

= 2022 \(\times\) (5 +15)  - 20 \(\times\) 2021

= 2022 \(\times\) 20 - 20 \(\times\) 2021

= 20 \(\times\) (2022 - 2021)

= 20 \(\times\) 1

= 20 

kết quả là 1022 nhé bạn

=2022(123*12-11)

=2962230

2022 × 123 × 12 - 2022 × 11

= 2022 × (123 × 12 - 11)

= 2022 × (1476 - 11)

= 2022 × 1465

= 2962230

(125.7²-5.35²):2021²⁰²²

=(5³.7²-5³.7²):2021²⁰²²

=0:2021²⁰²²

=0

100% ĐÚNG

(125.7^2-5.35^2): 2021^2022

= ( 125.49 - 5. 875 ) : 4086462

= ( 6125 - 4375 ) : 4086462

= 4086462 : 1750

= 2335,12114

2023/2022=1+1/2022

2022/2021=1+1/2021

mà 2022>2021

nên 2023/2022<2022/2021

TA có: \(3a-b=\frac12\left(a+b\right)\)

=>2(3a-b)=a+b

=>6a-2b=a+b

=>5a=3b

=>a=0,6b

\(C=\frac{a^{2022}+3^{2022}}{b^{2022}+5^{2022}}\)

\(=\frac{\left(0,6b\right)^{2022}+3^{2022}}{b^{2022}+5^{2022}}\)

\(=\frac{\left(0,6\right)^{2022}\left(b^{2022}+5^{2022}\right)}{b^{2022}+5^{2022}}=\left(0,6\right)^{2022}=\left(\frac35\right)^{2022}\)

1-2+3-4+...+2021-2022+2023

=(1-2)+(3-4)+...+(2021-2022)+2023

=(-1)+(-1)+(-1)+...+(-1)+2023

=(-1011)+2023

=1012

Thanks