Hướng dẫn giải:

a) 987 x 23 + 987 x 77

= 987 x (23 + 77)

= 987 x 100

= 98700

b) 2928 x 69 – 1928 x 69

= (2928 – 1928) x 69

= 1000 x 69

= 69000

`@` `\text {Ans}`

`\downarrow`

`69 \times 36 - 38 \times 18`

`= 69 \times 2 \times 18 - 38 \times 18`

`= 18 \times (69 \times 2 - 38)`

`= 18 \times (138 - 38)`

`= 18 \times 100`

`=1800`

=18(69*2-38)

=18*100=1800

20/11*33/23*69/180=20/11*33/23*23/60

\(=\frac{74+69}{75+89}\)\(=\frac{10}{13}\)

69026,73 - 25,27 = 69001,46

chúc bn hok tốt ^^

69026,73 - 25,27 = 69001,46

k nhé

69001,46 nha

@@@@@@@@@@@@@@@@@@@@@@@@@@@

1059 x 69 + 1059 x 30 + 1059

=1059 x (69+30+1)

=1059 x 100

=10590

cho tui 1 coin nha 

= 1059 x ( 69 + 30 + 1)

= 1059 x 100

= 105900

    1059 x 69 +1059 x 30 + 1059

=   1059 x 69 + 1059 x 30 + 1059 x1

=   1059 x ( 69 + 30 +1)

=    1059 x 100

=    105 900 

20/11*33/23*69/180=1/1*3/1*3/9=1 

\(\frac{20}{11}\cdot\frac{33}{23}\cdot\frac{69}{180}=\frac{20\cdot33\cdot69}{11\cdot23\cdot180}=\frac{9}{9}=1\)

Để mình ghi lại đề bài:

\(\frac{20}{11}\) x \(\frac{33}{23}\) x \(\frac{69}{180}\)

=\(\frac{20x33x69}{11x23x180}\)(x là nhân nhé)

=\(\frac{20x11x3x23x3}{11x23x20x9}\)

=\(\frac{20x11x3x23x3}{11x23x20x3x3}\)=1