Bài 1: Thực hiện phép tính
(9/14-9/21):(4/5+5/6) b) 7/10-(-3)/4+(-5)/6-1/5+(-2)/3 c) 〖(-2)〗^3.(3/4-0,25):2 1/4-1 1/6
d) -1/7.(9 1/2-8,75):2/7+0,625:1 2/3 e) 15/18-(5/18.1/15+1 1/12) f) (-1/2)^2:1/4-2(-1/2)^3
g) 7/8.(-5)/9-7/8.4/9+5 7/8 i) (-1)/4.13 9/11-0,25.6 2/11 k) 3/5.7+3/7.9+⋯+3/59.6 n) (20% – 1,4).( – 5)2 – (1 – ).0,5
Bài 1: Thực hiện phép tính (9/14-9/21):(4/5+5/6) b) 7/10-(-3)/4+(-5)/6-1/5+(-2)/3 c) 〖(-2)〗^3.(3/4-0,25):2 1/4-1 1/6 d) -1/7.(9 1/2-8,75)
By Elliana
a) `(9/14-9/21):(4/5+5/6)=3/14:49/30=45/343`
b) `7/10-(-3/4)+(-5/6)-1/5+(-2/3)=(7/10-1/5)-(5/6+2/3)+3/4`
`=9/10-3/2+3/4=3/20`
c) `(-2)^3.(3/4-0,25):2 1/4-1 1/6=(-8).1/2:9/4-7/6=-16/9-7/6=-53/18`
d) `-1/7.(9 1/2-8,75):2/7+0,625:1 2/3=-1/7.3/4:2/7+5/8:5/3=-3/8+3/8=0`
e) `15/18-(5/18. 1/15+1 1/12)=15/18-(1/54+13/12)=15/18-119/108=-29/108`
f) `(-1/2)^2:1/4-2(-1/2)^3=1/4:1/4+2.1/8=1+1/4=5/4`
Tí mk lm tiếp!
`d)` `-1/7` `×` `(9 1/2 – 8,75)` `:` `2/7` `+` `0,625` `:` `1 2/3`
`=` `-1/7` `×` `(19/2 – 35/4)` `:` `2/7` `+` `5/8` `×` `3/5`
`=` `-1/7` `×` `(38/4 – 35/4)` `×` `7/2` `+` `3/8`
`=` `-1/7` `×` `3/4` `×` `7/2` `+` `3/8`
`=` `-3/28` `×` `7/2` `+` `3/8`
`=` `-3/8` `+` `3/8`
`=` `0`
`e)` `15/18` `-` `(5/18 × 1/15 + 1 1/12)`
`=` `15/18` `-` `(1/54 + 13/12)`
`=` `15/18` `-` `(2/108 + 117/108)`
`=` `15/18` `-` `119/108`
`=` `90/108` `-` `119/108`
`=` `-29/108`
`f)` `(-1/2)^2` `:` `1/4` `-` `2` `×` `(-1/2)^3`
`=` `(1/4) `×` `4` `-` `2` `×` `(-1/8)`
`=` `1` `-` `-1/4`
`=` `1` `+` `1/4`
`=` `5/4`