Dễ 1+1=2

1:

a: =23/27-11/17+4/27+28/17

=23/27+4/27+28/17-11/17

=1+1=2

b: \(=\dfrac{2}{3}\cdot\left(\dfrac{7}{9}+\dfrac{2}{9}\right)-\dfrac{2}{9}\)

=2/3-2/9

=6/9-2/9

=4/9

c: \(=\dfrac{11}{5}\cdot\dfrac{7}{3}-\dfrac{1}{3}\cdot\dfrac{11}{5}\)

=11/5(7/3-1/3)

=11/5*2

=22/5

d: \(=\dfrac{3}{2}\cdot\dfrac{4}{3}\cdot...\cdot\dfrac{2024}{2023}=\dfrac{2024}{2}=1012\)

e: \(=\dfrac{1}{2}\cdot\dfrac{2}{3}\cdot...\cdot\dfrac{2022}{2023}=\dfrac{1}{2023}\)

\(\frac{11.4-11}{2-13}=\frac{11.\left(4-1\right)}{-11}=\frac{11.3}{-11}=\frac{33}{-11}=-3\)

Vậy kết quả của biểu thức = 3 là sai

Phải thành -3 mới đúng!

Chúc em học tốt!

*Rút gọn :

`(8.5-8.2)/16=(8.(5-2))/(8.2)=(8.3)/(8.2)=3/2`

`(11.4-11)/(2-13)=(11.(4-1))/(-11)=(11.3)/(-1.11)=3/(-1)=-3`

*Quy đồng :

- Ta có : `-3=(-3)/1`

UCLN(2,1)=2

$\to\begin{cases} \dfrac32=\dfrac32\\\dfrac{-3}1=\dfrac{-6}2\end{cases}$

\(A=\frac{2}{13}.\frac{5}{9}+\frac{2}{13}.\frac{4}{9}+\frac{11}{13}=\frac{2}{13}.\left(\frac{5}{9}+\frac{4}{9}\right)+\frac{11}{3}\)

                                                           \(=\frac{2}{13}.1+\frac{11}{13}\)

                                                             \(=\frac{2}{13}+\frac{11}{13}=1\)

\(A=\frac{2}{13}\cdot\frac{5}{9}+\frac{2}{13}\cdot\frac{4}{9}+\frac{11}{13}\)

\(A=\frac{2}{13}\left(\frac{5}{9}+\frac{4}{9}\right)+\frac{11}{13}\)

\(A=\frac{2}{13}\cdot1+\frac{11}{13}\)

\(A=\frac{2}{13}+\frac{11}{13}\)

\(A=\frac{13}{13}=1\)

2/13×(5/9+4/9)+11/13

2/13×1+11/13

2/13+11/13

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