Bài 1: Tính hợp lí
1) 2155 – ( 174 + 2155 ) + ( – 68 + 174 )
2) – 25 . 72 + 25 . 21 – 49 . 25
3) 35 . ( 14 – 23 ) – 23 . ( 14 – 23 )
4) 8154 – ( 674 + 8154 ) + ( – 98 + 674 )
5) – 25 . 21 + 25 . 72 + 49 . 25
6) 27 . ( 13 – 16 ) – 16 . ( 13 – 16 )
7) – 326 – ( 115 – 326 )
8) 36 . 82 + 18 + 36
9) 34 . ( – 84 ) + 17 . ( -32 )
Các bn yêu quý ơi giúp mk vs mk dg cần trả lời ngay và luôn. mk cảm ơn tất cả các bn nhiều
1) 2155 – (174 + 2155) + (-68+174)
= 2155 – 174 – 2155 + (-68) + 174
=(2155 – 2155) – (174 – 174) + (-68)
= -68
2) -25 . 72 + 25 . 21 – 49 . 25
= 25 . (-72 + 21 – 49)
= 25 . (-100) = -2500
3)35 . ( 14 – 23 ) – 23 . ( 14 – 23 )
=(-35.23+23.35)+(35.14-23.14)
=0.14+12
=168
4) 8154 – (674 + 8154) + (-98 + 674)
= 8154 – 674 – 8154 + (-98) + 674
= (8154 – 8154) – (674 – 674) + (-98)
= -98
5) -25.21+ 25.72 + 49.25
= 25. (-21 + 72 + 49)
= 25. 100 = 2500
6) 27 . ( 13 – 16 ) – 16 . ( 13 – 16 )
= (13 – 16) (27 – 16)
= -3 . 11
= -33
$@PULOVN$
Bài 1:
1) 2155 – ( 174 + 2155 ) + ( – 68 + 174 )
= 2155 – 174 – 2155 – 68 + 174
= ( 2155 – 2155) + (174 – 174) – 68
= -68
2) – 25 . 72 + 25 . 21 – 49 . 25
= 25 (-72 + 21 – 49)
= 25 . (-100)
= -2500
3) 35 . ( 14 – 23 ) – 23 . ( 14 – 23 )
= ( 14 – 23) (35 – 23)
= -9 . 12
= -108
4) 8154 – ( 674 + 8154 ) + ( – 98 + 674 )
= 8154 – 674 – 8154 – 98 + 674
= (8154 – 8154) + (674 – 674) – 98
= -98
5) – 25 . 21 + 25 . 72 + 49 . 25
= 25 (-21 + 72 + 49)
= 25 . 100
= 2500
6) 27 . ( 13 – 16 ) – 16 . ( 13 – 16 )
= (13 – 16) (27 – 16)
= -3 . 11
= -33
7) – 326 – ( 115 – 326 )
= -326 – 115 + 326
= (-326 + 326) – 115
= -115
8) 36 . 82 + 18 . 36
= 36(82 + 18)
= 36 . 100
= 3600
9) 34 . ( – 84 ) + 17 . ( -32 )
= 34 . 2 .(-42) + 17 . 4 . (-8)
= 68 . (-42) + 68 . (-8)
= 68 . (-42 – 8)
= 68 . (-50)
= -3400