1 . Lan can't speak E.

2 . I haven't three rabbit.

3 . Thu isn't a singer.

4 . The children aren't at school.

5 . The dogs don't eat meat.

24 kg = 2,4 tạ

3 tạ = 30 kg.

625⁵ và 125⁵

⇒ ( 5⁴ )⁵   và ( 5³)⁵

⇒ 5²⁰ và 5¹⁵

⇔ 625⁵ > 125⁵.

là đắt.

50 - [ ( 50 - 2³ . 5 ) : 2 + 34 ]

= 50 - [ ( 50 - 40 ) : 2 + 34 ]

= 50 - [  10 : 2 + 34 ]

= 50 - [ 5 + 34 ]

= 50 - 39

= 11.

10² - [ 60 : ( 5⁶ : 5⁴ - 3 . 5) ]

= 100 - [ 60 : ( 25 - 15 ) ]

= 100 - [ 60 : 10 ] 

= 100 - 6

= 94.

What : cái gì

76 - { 2 . [ 2 . 5² - ( 31 - 2.3 ) ] } + 3. 25

= 76 - { 2 .[  50 - ( 31 - 6 ) ] } + 75

= 76 - {2 . [ 50 - 25 ]  } + 75

= 76 - { 2 . 25 } + 75

= 76 - 100 + 75

= 51.

50 - [ ( 20 - 2³ ) : 2 + 34]

= 50 - [ ( 20 - 8 ) : 2 + 34 ]

= 50 - [ 12 : 2 + 34 ]

= 50 - [ 6 + 34 ]

= 50 - 40

=10.

91,52 : 26 = 3,52.