6/7.8/13+9//13.6/7-3/13.6/7
mình ko biết chọn chủ đề nên mình bấm đại hihi
6/7.8/13+6/13.9/7-4/13.6/7=?
1. thực hiện phép tính
a, 2/3-5/6+3/4
b, 6/7.8/13+6/13.9/7-4/13.6/7
c, 19. (-26)
\(a,\dfrac{2}{3}-\dfrac{5}{6}+\dfrac{3}{4}\)
\(=(\dfrac{2}{3}+\dfrac{3}{4})-\dfrac{5}{6}\)
\(=\dfrac{7}{12}\)
\(b,\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{13}.\dfrac{9}{7}-\dfrac{-4}{13}.\dfrac{6}{7}\)
\(=\dfrac{6}{7}.(\dfrac{8}{13}-\dfrac{4}{13})+(\dfrac{6}{13}.\dfrac{9}{7})\)
\(=(\dfrac{6}{7}.\dfrac{4}{13})+\dfrac{54}{91}\)
\(=\dfrac{24}{91}+\dfrac{54}{91}\)
\(=\dfrac{78}{91}=\dfrac{6}{7}\)
\(c,19.(-26)\)
\(=-494\)
a) `2/3 - 5/6 +3/4`
`=4/6-5/6+3/4`
`=-1/6+3/4`
`=-4/24+18/24`
`=14/24=7/12`
b) `6/7 .8/13 +6/13 .9/7 -4/13 .6/7`
`=6/7 .(8/13-4/13) + 6/13 .9/7`
`=6/7 . 4/13 + 6/13 . 9/7`
`= 6/13 .4/7 +6/13 .9/7`
`=6/13 . (4/7+9/7)`
`=6/13 . 13/7`
`=6/7`
c) `19.(-26)`
`=(1-20).(20+6)`
`=20+6-400-120`
`=-494`
/ là phân số
/ là phân số
1.=6/7.8/13+6/7.9/13-3/13.6/7=6/7.(8/13+9/13-3/13)=6/7.14/13=12/13
8)Tính nhanh :
a) -3/7+5/13+ -4/7
b)-5/8+3/4+ -1/5+-3/8+1/4
c)6/7.8/13+6/7.9/13+ -3/13.6/7
d)-5/7.2/11+ -5/7.9/11+1 5/7
e)11 3/13 - (2 4/7+5 3/13)
f) (1-1/2)(1-1/3)(1-1/4)(1-1/5)
Tính : ( chi tiết ) 6/7 . 8/13 +6/13.9/7 - 4/13.6/7
`6 / 7 . 8 / 13 + 6 / 13 . 9 / 7 - 4 / 13 . 6 / 7`
`= 6 / 7 . 8 / 13 + 6 / 7 . 9 / 13 - 4 / 13 . 6 / 7`
`= 6 / 7 ( 8 / 13 + 9 / 13 - 4 / 13 )`
`= 6 / 7 . 13 / 13`
`= 6 / 7`
\(\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{13}.\dfrac{9}{7}-\dfrac{4}{13}.\dfrac{6}{7}\\ =\dfrac{6}{7}.\dfrac{8}{13}+\dfrac{6}{7}.\dfrac{9}{13}-\dfrac{4}{13}.\dfrac{6}{7}\\ =\dfrac{6}{7}\left(\dfrac{8}{13}+\dfrac{9}{13}-\dfrac{4}{13}\right)\\ =\dfrac{6}{7}.\dfrac{13}{13}\\ =\dfrac{6}{7}.1\\ =\dfrac{6}{7}\)
67.813+613.97−413.67=67.813+67.913−413.67=67(813+913−413)=67.1313=67.1=67
Tính nhanh(nếu có thể)
a.75%-1 1/2+0,5.13/7
b.6/7-8/13+6/13.9/7-3/13.6/7
c.(2/9:5/3+1/3:5/3)2 -(1/3-5/8)
e.7/8.7/13+7/8.9/13-7/8.3/13
Tính : ( chi tiết ) 6/7 . 8/3 +6/13.9/7 - 4/13.6/7
`6 / 7 . 8 / 13 + 6 / 13 . 9 / 7 - 4 / 13 . 6 / 7`
`= 6 / 7 . 8 / 13 + 6 / 7 . 9 / 13 - 4 / 13 . 6 / 7`
`= 6 / 7 ( 8 / 13 + 9 / 13 - 4 / 13 )`
`= 6 / 7 . 13 / 13`
`= 6 / 7`
Đề phải là `6 / 7 . 8 / 13 + 6 / 13 . 9 / 7 - 4 / 13 . 6 / 7` chứ nhỉ ?
Ai Giúp mình bài rút gọn phân số này với a) 103/3090 b) 7314/-18126 c)23.5-23.8/414 d) 7/102-8.102 e) -13.6+12.5/6.(-7)-(-4).6 f) 914.255.(-8)7/(-18)12.6253.(-24)3
a)-4/11+5/6+7/11-5/6
b)-5/6.7/13+19/13.6/-5+2/5
c)3/7.(-0,5+3/2)-2/7:25%
mọi người giúp e vs ạ
e cần gấp
a; - \(\dfrac{4}{11}\) + \(\dfrac{5}{6}\) + \(\dfrac{7}{11}\) - \(\dfrac{5}{6}\)
= (-\(\dfrac{4}{11}\) + \(\dfrac{7}{11}\)) + (\(\dfrac{5}{6}\) - \(\dfrac{5}{6}\))
= - \(\dfrac{3}{11}\) + 0
= - \(\dfrac{3}{11}\)
b; -\(\dfrac{5}{6}\).\(\dfrac{7}{13}\) + \(\dfrac{19}{13}\).\(\dfrac{6}{-5}\) + \(\dfrac{2}{5}\)
= - \(\dfrac{35}{78}\) - \(\dfrac{114}{65}\) + \(\dfrac{2}{5}\)
= - \(\dfrac{859}{390}\) + \(\dfrac{2}{5}\)
= - \(\dfrac{703}{390}\)
c; \(\dfrac{3}{7}\).(-0,5 + \(\dfrac{3}{2}\)) -\(\dfrac{2}{7}\) : 25%)
= \(\dfrac{3}{7}\).1 - \(\dfrac{8}{7}\)
= \(-\dfrac{5}{7}\)