Bài 1

\(d,66\cdot25+5\cdot66+66\cdot14+33\cdot66\)

\(=66\left(25+5+14+33\right)\)

\(=66\cdot77\)

\(=5082\)

Hình như chép sai đề vì không thể nào tính nhanh đc

Bài 2

\(7+\left(63:x-11\right)\cdot23=237\)

\(\Leftrightarrow\left(63:x-11\right)\cdot23=230\)

\(\Leftrightarrow63:X-11=10\)

\(\Leftrightarrow63:x=21\)

\(\Leftrightarrow x=3\)

Bài 1 :

\(d,66.25+5.66+66.14+33.66\)

\(=66.\left(25+5+14+33\right)\)

\(=66.77\)

\(=5082\)

Bài 2 :

\(7+\left(63:x-11\right).23=237\)

\(\Leftrightarrow\left(63:x-11\right).23=230\)

\(\Leftrightarrow63:x-11=10\)

\(\Leftrightarrow63:x=21\)

\(\Leftrightarrow x=3\)

Vậy x = 3 .

Học tốt nhé

66.25+5.66+66.14+33.66

=66.(25+5+14+33)

=66.77

=5082

7+(63:x-11).23=237

(63:x-11).23=237-7

(63:x-11).23=230

(63:x-11)=230:23

(63:x-11)=10

63:x=10+11

63:x=21

x=63:21

x=3

vậy x=3

II Put the verbs into the most suitable passive form

1) There's someone behind us . I think we are being followed ( follow )

2) A mystery is something that can't be explained ( can't / explain )

3) We didn't play football yesterday .That match was cancalled ( cancle )

4) The televison has been repaired ( repair ) . It's working again now.

5) The church tower is being restored ( restore ). The work is almost finished .

6) How old is the tower ? It is believed ( believe ) to be over 600 years old .

7) If I didn't do my job properly , I would be sacked ( would / sack )

8) A : I left some papers on the desk last night and I can't find them now

    B : They might have been thrown ( might / throw ) away

9) I learned to swim when I was very young . I was taught ( teach ) by my mother .

10) After being arrested ( arrest ), I was taken to the police station .

11) This road is being repaired ( repair ) so we have to take another road .

12) Two people are reported ( report ) to have been injured ( injure ) in an explosion at a factory early this morning .

13) I haven't receive the letter . It might be sent ( might / send ) to the wrong address .

14) The vegtables didn't taste very good . They had been cooked ( cook ) for too long .

15) The examination papers are scored by machine . The students will be told (tell) their results next week .

Nhìn là biết bạn sai nốt bài I rồi

Bn cx thek nhá????

23+1+2019 =2043

kb nhoa!!

222 xu

Đang pùn nè!!!!

ib lun điz!!!!

mik nhầm câu 3 nhk k phải câu 1

66-6+7+23-18+2

= (66-6) + (7+23) - (18-2)

= (60 + 30) - 16

= 90 - 16

= 74

66 - 6 + 7 + 23 - 18 + 2

= 60 + 30 - 18 + 2

= 90 - 18 + 2

=72 + 2

= 74

66 - 6 + 7 +23 - 18 + 2 

= ( 66 - 6 ) + ( 7 + 23 ) - 18 +  2 

=     60      +      30 - 18 + 2

= 90 - 18 + 2 

= 90 + ( 18 - 2 )

= 90 + 16

= 106 

66-6+7+23-18-2=(66-6)+(7+23)-(18-2)

                          =60+30+16

                          =106

sai rồi

66 - 6 + 7 + 23 - 18 + 2 

= 60   +   30    -  20 

=       90         -  20 

=      70 

a) 98 + 87 + 76 + ... + 32 + 21 - 12 - 23 - ... - 78 - 89

= ( 98 - 89 ) + ( 87 - 78 ) + ... + ( 32 - 23 ) + ( 21 - 12 )

= 9 + 9 + 9 + ... + 9 ( ? số 9 )

Từ 21 đến 98 với khoảng cách 11 có số các số hạng là : ( 98 - 21 ) / 11 + 1 = 8 ( số hạng )

-> 9 * 8 = 72

b) ( 66 - 1 ) * ( 66 - 2 ) * ... * ( 66 - 98 ) * ( 66 - 99 )

Trong tích trên có thừa số 66 - 66 với giá trị bằng 0.

Vậy tích trên bằng 0.

c) cái này phức tạp lắm, rất khó mà tính

câu hỏi này dễ thật