Thuc hien cac phep tinh bang cach hop li:
a)(4 2/5+2 3/7)-(2 2/5-5 4/7)
b)5/7*23/25-5/7*9/25
c)13,5*7-5*2,7*3+3*4,5*6
d)1/2:0,5-1/4:0,25+1/8:0,125-1/10:0,1
e)45*15+28/45*16-17
Giai ho minh voi
/ la phan so nha
Thuc hien cac phep tinh bang cach hop li: a)(4 2/5+2 3/7)-(2 2/5-5 4/7) b)5/7*23/25-5/7*9/25 c)13,5*7-5*2,7*3+3*4,5*6 d)1/2:0,5-1/4:0,25+1/8:0,125-1/1
By Aaliyah
Đáp án:
Giải thích các bước giải:
a, (42/5 + 23/7) – (22/5 – 54/7)
= 42/5 + 23/7 – 22/5 + 54/7
= (42/5 -22/5) + (23/7 + 54/7)
= 20/5 + 77/7
= 4 + 11
= 15
b, 5/7 x 23/25 – 5/7 x 9/25
= 5/7 x (23/25 – 9/25)
= 5/7 x 14/25
= 2/5 (đáp án đã đc rút gọn)
c, 13,5 x 7 – 5 x 2,7 x 3 + 3 x 4,5 x 6
= 13,5 x 7 – 13,5 x 3 + 13,5 x 6
= 13,5 x (7 – 3 + 6)
= 13,5 x 10
= 135
d, 1/2 : 0,5 – 1/4 : 0,25 + 1/8 : 0,125 – 1/10 : 0,1
= 1 – 1 + 1 – 1
= 0 + 0
= 0
Câu e mình ko bt làm nha
chúc bạn học tốt (nếu sai hoặc thiếu mong bạn sửa giúp)
A.
( `42/5` + `23/7` ) – ( `22/5` – `54/7` )
= `42/5` + `23/7` – `22/5` + `54/7`
= ( `42/5` – `22/5` ) + ( `23/7` + `54/7` )
= `20/5` + `77/7`
= `4` + `11`
= `15`
B.
`5/7` x `23/25` – `5/7` x `9/25`
= `5/7` x ( `23/25` – `9/25` )
= `5/7` x `14/25`
= `70/175` = `2/5`
C.
`13,5` x `7` – `5` x `2,7` x `3` + `3` x `4,5` x `6`
= `13,5` x `7` – `13,5` x `3` + `13,5` x `6`
= `13,5` x ( `7` – `3` + `6` )
= `13,5` x `10`
= `135`
D.
`1/2` ÷ `0,5` – `1/4` ÷ `0,25` + `1/8` ÷ `0,125` – `1/10` ÷ `0,1`
= `1` – `1` + `1` – `1`
= `0` + `0`
= `0`
E.
`45` × `15` + `28/45` × `16` – `17`
= `675` + `28/45` × `16` – `17`
= `675` + `9,9` – `17`
= `684,9` – `17`
= `667,9`
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