Question

Giúp mk bài 2,3 với

 

Answer 1

Bài 2:

a, 27 . 77 + 24 . 27 - 27

= 27 . 77 + 24 . 27 - 27 . 1

= 27 . ( 77 + 24 - 1 )

= 27 . 100

= 2700

b,

\(174:\left\{2\cdot\left[36+\left(4^2-23\right)\right]\right\}\)

\(=174:\left\{2\cdot\left[36+\left(16-23\right)\right]\right\}\)

\(=174:\left\{2\cdot\left[36-7\right]\right\}\)

\(=174:\left\{2\cdot29\right\}\)

\(=174:58\)

\(=3\)

c,

\(145+\left[322+\left(-145\right)+\left(-302\right)\right]\)

\(=145+322-145-302\) ( phá ngoặc )

\(=145-145+322-302\) ( giao hoán + kết hợp )

\(=0+20\)

\(=20\)

d,

\(132+\left(-75\right)+1043+\left(-150\right)\)

\(=132-75+1043-150\)

\(=57+893\)

\(=950\)

Bài 3:

a,

9x + 2 = 20

=> 9x = 20 -2

9x = 18

x = 18 : 9

x = 2

Vậy x = 3

b,

6x - 4x = 2² . 16

x . ( 6 - 4 ) = 4 . 16

2x = 64

=> x = 64 : 2

x = 32

Vậy x = 32

c,

x - 2 = ( -6 ) - ( - 17 )

x - 2 = -6 + 17

x - 2 = 11

x = 11 + 2

x = 13

Vậy x = 13

Answer 2

câu 1:

a) M={0;1;2;3;4;5;6;7;8.}

b)có 46 phần tử