Question

Bài 1: Thực hiện phép tính 

a, ( - 168 ) + 72 . ( - 168) + ( - 168) . 27

b, 2² . ( - 3) - ( 1¹⁰ + 8 ) : ( - 3)²

^{c, ( - 1075 ) - ( 29 - 1075 )}

^{d, ( - 9 ) + ( - 11) + 21 + ( - 1)}

^{e, 30 + 12 + ( - 20 ) + ( - 12 ) - ( 30 - 20 ) + ( 12 - 12)}

^{g, ( 13 - 135 + 49 ) - ( 13 + 49 )}

^{h, 35 - { 12 - [ ( - 14 ) + ( - 2 ) } ]}

Bài 2 : Tìm x

a, x - 35 = ( - 12 ) - 3

b, 1/4 + 1/3 : 3x = - 5

c, 2 ^{x - 1} = 8

 

 

Answer 1

nhiều quá bạn chọn câu nào jhos nhất thôi

Answer 2

a, ( - 168 ) + 72 . ( - 168 ) + ( - 168 ) . 27

= ( - 168 ) + ( - 12096 ) + ( - 4536 )

= - 12264 + - 4536

= - 16800

b, 2² . ( - 3 ) - ( 1¹⁰ + 8 ) : ( - 3 )²

= 4 . ( - 3 ) - ( 1 + 8 ) : 9

= ( - 12 ) - 9 : 9

= ( - 12 ) - 1

= - 13

c, ( - 1075 ) - ( 29 - 1075 )

= ( - 1075 ) - ( - 1046 )

= - 29

d, ( - 9 ) + ( - 11 )  + 21 + ( - 1 )

= - 20 + 21 + ( - 1 )

= 1 + - 1

= 0

e, 30 + 12 + ( - 20 ) + ( - 12 ) - ( 30 - 20 ) + ( 12 - 12 ) 

= 42 + ( - 20 ) + ( - 12 ) - 10 + 0

= 22 + ( - 12 ) - 10 + 0

= 10 - 10 + 0

= 0 + 0

= 0

g, ( 13 - 135 + 49 ) - ( 13 + 49 )

= [( - 122 ) + 49  ] - 62

= ( - 73 ) - 62

= - 135

h, 35 - { 12 - [ ( - 14 ) + ( - 2 ) } ]

= 35 - { 12 - ( - 16 ) }

= 35 - 28

= 7

Bài 2:

a. x - 35 = ( - 12 ) - 3

    x - 35 = - 15

         x  = - 15 + 35

         x  = 20

b, \(\frac{1}{4}\)+ \(\frac{1}{3}\): 3x = - 5

\(\frac{3}{12}+\frac{4}{12}\): 3x = - 5

\(\frac{7}{12}\): 3x =  - 5

3x = \(\frac{7}{12}\): - 5

3x = \(\frac{-7}{60}\)

 x = \(\frac{-7}{60}\): 3

 x = \(\frac{-7}{180}\)

c,2^x-1 = 8

2^x-1 = 2⁴

x = 4 + 1

x = 5

Answer 3

Mình chữa lại phần c bài 2 nha:

2^x-1 = 8

2^x-1 = 2³

x = 3 + 1

x = 4