\(\dfrac{5}{7}\)x\(\dfrac{5 }{11}\)\(+\dfrac{5}{7}\)\(\text{x}\dfrac{2}{11}\)\(-\dfrac{5}{7}\)\(\text{x}\dfrac{14}{11}\)
a,\(\dfrac{1}{7}\text{x}\dfrac{2}{7}+\dfrac{1}{7}\text{x}\dfrac{5}{7}+\dfrac{6}{7}\) b,\(\dfrac{6}{11}\text{x}\dfrac{4}{9}+\dfrac{6}{11}\text{x}\dfrac{7}{9}-\dfrac{6}{11}\text{x}\dfrac{2}{9}\)
c, \(\dfrac{4}{25}\text{x}\dfrac{5}{8}\text{x}\dfrac{25}{4}\text{x}24\)
`a)1/7xx2/7+1/7xx5/7+6/7`
`=1/7xx(2/7+5/7)+6/7`
`=1/7xx1+6/7`
`=1/7+6/7=1`
`b)6/11xx4/9+6/11xx7/9-6/11xx2/9`
`=6/11xx(4/9+7/9-2/9)`
`=6/11xx9/9`
`=6/11`
Sorry nãy ghi thiếu.
`c)4/25xx5/8xx25/4xx24`
`=(4xx5xx25xx24)/(25xx8xx4)`
`=(4xx5xx24)/(4xx8)`
`=(5xx24)/8`
`=5xx3=15`
a, \(\dfrac{1}{7}.\dfrac{2}{7}+\dfrac{1}{7}.\dfrac{5}{7}+\dfrac{6}{7}\)
\(=\dfrac{1}{7}.\left(\dfrac{2}{7}+\dfrac{5}{7}\right)+\dfrac{6}{7}\)
\(=\dfrac{1}{7}.1+\dfrac{6}{7}\)
\(=\dfrac{1}{7}+\dfrac{6}{7}=1\)
b, \(\dfrac{6}{11}.\dfrac{4}{9}+\dfrac{6}{11}.\dfrac{7}{9}-\dfrac{6}{11}.\dfrac{2}{9}\)
\(=\dfrac{6}{11}.\left(\dfrac{4}{9}+\dfrac{7}{9}-\dfrac{2}{9}\right)\)
\(=\dfrac{6}{11}.1=\dfrac{6}{11}\)
c, \(\dfrac{4}{25}.\dfrac{5}{8}.\dfrac{25}{4}.24\)
\(=\left(\dfrac{4}{25}.\dfrac{25}{4}\right).\left(\dfrac{5}{8}.24\right)\)
\(=1.15=15\)
1.Tính
\(a,5\text{x}\dfrac{7}{3}\) \(b,\dfrac{13}{4}:7\)
2.Tính
\(a,\dfrac{3}{7}+\dfrac{2}{5}+\dfrac{3}{4}\) \(b,\dfrac{9}{7}-\dfrac{5}{11}\text{x}\dfrac{11}{7}\) \(c,\dfrac{3}{5}\text{x}\dfrac{5}{7}\text{+}\dfrac{4}{7}\) \(d,\dfrac{7}{9}\text{x}\dfrac{2}{5}:\dfrac{3}{11}\) e,\(\dfrac{9}{7}+\dfrac{2}{3}-\dfrac{1}{4}\)
g,\(\dfrac{4}{9}:\dfrac{3}{5}\text{x}\dfrac{2}{11}\) h,\(\dfrac{7}{2}-\dfrac{3}{10}:\dfrac{2}{5}\)
\(a,5x\dfrac{7}{3}=\dfrac{5}{1}x\dfrac{7}{3}=\dfrac{35}{3};b,\dfrac{13}{4}:7=\dfrac{13}{4} :\dfrac{7}{1}=\dfrac{13}{4}x\dfrac{1}{7}=\dfrac{13}{28}\)
\(\dfrac{3}{7}+\dfrac{2}{5}+\dfrac{3}{4}=\dfrac{60}{140}+\dfrac{56}{140}+\dfrac{105}{140}=\dfrac{221}{140}\)
\(\dfrac{9}{7}-\dfrac{5}{11}x\dfrac{11}{7}=\dfrac{9}{7}-\dfrac{5}{7}=\dfrac{4}{7}\)
a.,\(\dfrac{4}{5}+5\dfrac{1}{2}\text{x }\left(4,5-2\right)=\dfrac{7}{10}\) b,125%x\(\dfrac{17}{4}:\left(1\dfrac{5}{16}-0,5\right)+2008\)
c,\(\dfrac{5}{11}+\left(\dfrac{16}{11}+1\right)\) d, \(\dfrac{3}{17}+\dfrac{11}{4}+\dfrac{5}{8}+\dfrac{14}{17}+\dfrac{3}{8}\)
`a)4/5+5 1/2 xx (4,5-2)+7/10`
`=4/5+11/2*2,5+7/10`
`=0,8+2,2+0,7`
`=3+0,7=3,7`
`b)125%xx 17/4:(1 5/16-0,5)+2008`
`=1,25xx4,25:13/16+2008`
`=85/13+2008`
`=2014 7/13`
`c)5/11+(16/11+1)`
`=5/11+1+5/11+1`
`=2+10/11=32/11`
`d)3/17+11/4+5/8+14/17+3/8`
`=3/17+14/17+5/8+3/8+11/4`
`=1+1+11/4`
`=19/4`
a)
\(\dfrac{4}{5}+5\dfrac{1}{2}x\left(4,5-2\right)=\dfrac{7}{10}\)
<=> \(\dfrac{11}{2}x\times2,5=\dfrac{7}{10}-\dfrac{4}{5}=\dfrac{-1}{10}\)
<=> \(\dfrac{55}{4}x=\dfrac{-1}{10}< =>x=\dfrac{-2}{275}\)
b) \(125\%\times\dfrac{17}{4}:\left(1\dfrac{5}{16}-0,5\right)+2008\)
= \(\dfrac{85}{16}:\left(\dfrac{21}{16}-\dfrac{1}{2}\right)+2008=\dfrac{85}{16}:\dfrac{13}{16}+2008=\dfrac{26189}{13}\)
c) \(\dfrac{5}{11}+\left(\dfrac{16}{11}+1\right)\)
= \(\dfrac{21}{11}+1=\dfrac{32}{11}\)
d) \(\left(\dfrac{3}{17}+\dfrac{14}{17}\right)+\left(\dfrac{5}{8}+\dfrac{3}{8}\right)+\dfrac{11}{4}\)
= 1 + 1 + \(\dfrac{11}{4}\) = \(\dfrac{19}{4}\)
Tìm x, biết:
\(x=\dfrac{19}{11}\cdot\dfrac{5}{14}+\dfrac{1}{11}\cdot\dfrac{5}{7}-\sqrt{\dfrac{25}{4}}\cdot\dfrac{2}{11}\)
\(\dfrac{-5}{7}\)x\(\dfrac{2}{11}\)+\(\dfrac{-5}{7}\)x\(\dfrac{9}{11}\)+\(\dfrac{5}{7}\)
=5/7.-2/11+5/7.-9/11+5/7.1
=5/7.(-2/11+-9/11+1)
=5/7.0
=0
\(=\dfrac{5}{7}\times\left(\dfrac{-2}{11}+\dfrac{-9}{11}+1\right)=\dfrac{5}{7}\times\dfrac{0}{11}=0\)
\(\dfrac{1}{3}\)+\(\dfrac{5}{4}\) -\(\dfrac{7}{12}\) \(\dfrac{11}{14}\)x \((-\dfrac{4}{11})\)-\(\dfrac{5}{4}\):\(\dfrac{11}{4}\) 1.6x2\(\dfrac{1}{4}\) -1.6x3\(\dfrac{1}{2}\) giúp mình 3 câu này vs pls mai mình ktra rồi :<
Tính giá trị biểu thức:
(\(\dfrac{6}{11}+\dfrac{5}{11}\)) x \(\dfrac{3}{7}\) \(\dfrac{3}{5}x\dfrac{7}{9}-\dfrac{3}{5}x\dfrac{2}{9}\) \(\left(\dfrac{6}{7}-\dfrac{4}{7}\right):\dfrac{2}{5}\)
`(6/11 +5/11) xx 3/7`
`= 11/11xx 3/7`
`=1xx3/7`
`=3/7`
__
`3/5 xx 7/9 - 3/5 xx 2/9`
`= 3/5 xx (7/9-2/9)`
`= 3/5 xx 5/9`
`= 15/45`
`= 1/3`
__
`(6/7 -4/7):2/5`
`= 2/7 : 2/5`
`= 2/7 xx 5/2`
`= 10/14`
`= 5/7`
\(\left(\dfrac{6}{11}+\dfrac{5}{11}\right)\times\dfrac{3}{7}\)
\(=1\times\dfrac{3}{7}=\dfrac{3}{7}\)
___________
\(\dfrac{3}{5}\times\dfrac{7}{9}-\dfrac{3}{5}\times\dfrac{2}{9}\)
\(=\dfrac{3}{5}\times\left(\dfrac{7}{9}-\dfrac{2}{9}\right)\)
\(=\dfrac{3}{5}\times\dfrac{5}{9}\)
\(=\dfrac{1}{3}\)
__________
\(\left(\dfrac{6}{7}-\dfrac{4}{7}\right):\dfrac{2}{5}\)
\(=\dfrac{2}{7}\times\dfrac{5}{2}\)
\(=\dfrac{5}{7}\)
\(#WendyDang\)
\(\left(\dfrac{6}{11}+\dfrac{5}{11}\right)\times\dfrac{3}{7}\)
\(=\dfrac{11}{11}\times\dfrac{3}{7}\\ =1\times\dfrac{3}{7}=\dfrac{3}{7}\)
_____
\(\dfrac{3}{5}\times\dfrac{7}{9}-\dfrac{3}{5}\times\dfrac{2}{9}\\ =\dfrac{3}{5}\times\left(\dfrac{7}{9}-\dfrac{2}{9}\right)\\ =\dfrac{3}{5}\times\dfrac{5}{9}\\ =\dfrac{3}{9}\\ =\dfrac{1}{3}\)
_________
\(\left(\dfrac{6}{7}-\dfrac{4}{7}\right):\dfrac{2}{5}\\ =\dfrac{2}{7}\times\dfrac{5}{2}\\ =\dfrac{10}{14}\\ =\dfrac{5}{7}\)
\(A.\dfrac{-15}{28}x\dfrac{7}{25}\\ B.\dfrac{-5}{14}x\dfrac{7}{-3}\\ C.\dfrac{-1}{5}-\dfrac{7}{15}x\dfrac{9}{35}\\ D.\dfrac{-3}{4}-(\dfrac{-1}{2})^2\\ E.\dfrac{-4}{5}-\dfrac{-4}{5}x\dfrac{15}{16}\\F.(\dfrac{3}{4}+\dfrac{-7}{2})x(\dfrac{2}{11}+\dfrac{12}{22})\)
a: \(A=\dfrac{-7}{28}\cdot\dfrac{15}{25}=\dfrac{-1}{4}\cdot\dfrac{3}{5}=\dfrac{-3}{20}\)
b: \(B=\dfrac{-5\cdot7}{14\cdot\left(-3\right)}=\dfrac{35}{42}=\dfrac{5}{6}\)
c: \(C=\dfrac{-1}{5}-\dfrac{1}{5}\cdot\dfrac{3}{5}=\dfrac{-1}{5}-\dfrac{3}{25}=\dfrac{-8}{25}\)
d: \(D=\dfrac{-3}{4}-\dfrac{1}{4}=-1\)
e: \(E=\dfrac{-4}{5}\left(1-\dfrac{15}{16}\right)=\dfrac{-4}{5}\cdot\dfrac{1}{16}=\dfrac{-1}{20}\)
f: \(F=\dfrac{6-7}{4}\cdot\dfrac{4+12}{22}=\dfrac{-1}{4}\cdot\dfrac{8}{11}=\dfrac{-2}{11}\)
Tính:
a) \(\dfrac{1}{7}+\dfrac{2}{7}+\dfrac{3}{7}\) b) \(\dfrac{2}{9}+\dfrac{5}{9}+\dfrac{8}{9}\)
c) \(\dfrac{13}{14}-\dfrac{5}{14}-\dfrac{1}{14}\) d) \(\dfrac{7}{11}-\dfrac{4}{11}-\dfrac{3}{11}\)