=>1/7:x=3/14-3/7=3/14-6/14=-3/14
=>x=-1/7:3/14=-1/7*14/3=-14/21=-2/3
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Tính bằng cách thuận tiện nhất
B=\(\dfrac{1+\dfrac{1}{7}+\dfrac{1}{7^2}-\dfrac{1}{7^3}}{4+\dfrac{4}{7}+\dfrac{4}{7^2}-\dfrac{4}{7^3}}x\dfrac{858585}{313131}x\left(-1\dfrac{14}{17}\right)\)
Tìm x và y
\(\dfrac{x}{3}=\dfrac{y}{4}\)và\(x+y=14\)
\(\dfrac{2x+1}{5}=\dfrac{3y-2}{7}=\dfrac{2x+3y-1}{6x}\)
Tìm x, biết:
a) dfrac{3}{7}x - dfrac{2}{3}x dfrac{10}{21}
b) dfrac{7}{35} : (x - dfrac{1}{3}) -dfrac{2}{25}
c) 3.(x - dfrac{1}{2}) - 5. (x + dfrac{3}{5}) -x + dfrac{1}{5}
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Tìm x, biết:
a) \(\dfrac{3}{7}\)x - \(\dfrac{2}{3}\)x = \(\dfrac{10}{21}\)
b) \(\dfrac{7}{35}\) : (x - \(\dfrac{1}{3}\)) = \(-\dfrac{2}{25}\)
c) 3.(x - \(\dfrac{1}{2}\)) - 5. (x + \(\dfrac{3}{5}\)) = -x + \(\dfrac{1}{5}\)
Tìm x, biết:
a) dfrac{1}{20} - (x - dfrac{8}{5}) dfrac{1}{10}
b) dfrac{7}{4} - (x + dfrac{5}{3}) dfrac{-12}{5}
c) x - [dfrac{17}{2} - left(dfrac{-3}{7}+dfrac{5}{3}right)] dfrac{-1}{3}
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Tìm x, biết:
a) \(\dfrac{1}{20}\) - (x - \(\dfrac{8}{5}\)) = \(\dfrac{1}{10}\)
b) \(\dfrac{7}{4}\) - (x + \(\dfrac{5}{3}\)) = \(\dfrac{-12}{5}\)
c) x - [\(\dfrac{17}{2}\) - \(\left(\dfrac{-3}{7}+\dfrac{5}{3}\right)\)] = \(\dfrac{-1}{3}\)
Tìm x, biết:
a) dfrac{-1}{10} + dfrac{2}{5}x + dfrac{7}{20} dfrac{1}{10}
b) dfrac{1}{3} + dfrac{1}{2} : x -dfrac{1}{5}
c) -dfrac{2}{3} : x + dfrac{5}{8} -dfrac{7}{12}
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Tìm x, biết:
a) \(\dfrac{-1}{10}\) + \(\dfrac{2}{5}\)x + \(\dfrac{7}{20}\) = \(\dfrac{1}{10}\)
b) \(\dfrac{1}{3}\) + \(\dfrac{1}{2}\) : x= \(-\dfrac{1}{5}\)
c) \(-\dfrac{2}{3}\) : x + \(\dfrac{5}{8}\) = \(-\dfrac{7}{12}\)
Bài 4: tìm x:a) dfrac{4}{3} + (1,25 - x) 2,25b) dfrac{17}{6} - (x - dfrac{7}{6} ) dfrac{7}{4}c) 4 - (2x + 1) 3 - dfrac{1}{3}bài 15:a) (dfrac{-2}{3})9 : x (dfrac{-2}{3})b) x : (dfrac{4}{9})5 (dfrac{4}{9})4c) (x + 4)3 -125d) (10 - 5x)3 64e) (4x + 5)2 81Bài 16:a) 4 - 1dfrac{2}{5} - dfrac{8}{3}b) -0,6 - dfrac{-4}{9} - dfrac{16}{15}c) -dfrac{15}{4} . (dfrac{-7}{15}) . (-2dfrac{2}{5}Gi ải gấp giúp mình ạ, mình rất cần gấp
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Bài 4: tìm x:
a) \(\dfrac{4}{3}\) + (1,25 - x) = 2,25
b) \(\dfrac{17}{6}\) - (x - \(\dfrac{7}{6}\) ) = \(\dfrac{7}{4}\)
c) 4 - (2x + 1) = 3 - \(\dfrac{1}{3}\)
bài 15:
a) (\(\dfrac{-2}{3}\))9 : x = (\(\dfrac{-2}{3}\))
b) x : (\(\dfrac{4}{9}\))5 = (\(\dfrac{4}{9}\))4
c) (x + 4)3 = -125
d) (10 - 5x)3 = 64
e) (4x + 5)2 = 81
Bài 16:
a) 4 - \(1\dfrac{2}{5}\) - \(\dfrac{8}{3}\)
b) -0,6 - \(\dfrac{-4}{9}\) - \(\dfrac{16}{15}\)
c) \(-\dfrac{15}{4}\) . (\(\dfrac{-7}{15}\)) . (\(-2\dfrac{2}{5}\)
Gi ải gấp giúp mình ạ, mình rất cần gấp
4 tháng 5 2022 lúc 20:30
Câu 1: Thực hiện phép tính
a, \(40\dfrac{1}{4}:\dfrac{5}{7}-25\dfrac{1}{4}:\dfrac{5}{7}-\dfrac{1}{2021}\)
b, \(\left|\dfrac{-5}{9}\right|.\sqrt{81}-2021^0.\dfrac{16}{25}\)
Câu 2: Tìm x
\(3\left(x-\dfrac{1}{3}\right)-7\left(x+\dfrac{3}{7}\right)=-2x+\dfrac{1}{3}\)
Tìm x :
1) \(\left(-0,75x+\dfrac{5}{2}\right).\dfrac{4}{7}-\left(-\dfrac{1}{3}\right)=-\dfrac{5}{6}\)
2) \(\left(4x-9\right)\left(2,5+\dfrac{-7}{3}x\right)=0\)
3) \(\left|x-\dfrac{3}{4}\right|-\dfrac{1}{2}=0\)
4)\(\left(\dfrac{3}{5}-\dfrac{2}{3}x\right)^3=\dfrac{-64}{125}\)
Tìm x :
a, dfrac{11}{12} - (dfrac{2}{5} +x) dfrac{2}{3} b, x+dfrac{2}{3} dfrac{3}{5} - dfrac{-1}{6} c, x-[dfrac{17}{2} -(dfrac{-3}{7} + dfrac{5}{3} )]dfrac{-1}{3}
d,dfrac{9}{2} - [dfrac{2}{3} - (x+dfrac{7}{4} )] dfrac{-5}{4}
Mọi người giúp mình nha
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Tìm x :
a, \(\dfrac{11}{12}\) - (\(\dfrac{2}{5}\) +x) = \(\dfrac{2}{3}\) b, x+\(\dfrac{2}{3}\) =\(\dfrac{3}{5}\) - \(\dfrac{-1}{6}\) c, x-[\(\dfrac{17}{2}\) -(\(\dfrac{-3}{7}\) + \(\dfrac{5}{3}\) )]=\(\dfrac{-1}{3}\)
d,\(\dfrac{9}{2}\) - [\(\dfrac{2}{3}\) - (x+\(\dfrac{7}{4}\) )] =\(\dfrac{-5}{4}\)
Mọi người giúp mình nha
Tìm x, biếta)dfrac{1}{2}xx-dfrac{7}{3}dfrac{-5}{6}+dfrac{3}{4}xxb)dfrac{4}{5}xx-dfrac{6}{5}dfrac{1}{2}+dfrac{3}{2}xxc)dfrac{2}{5}x(3xx+dfrac{3}{4})1dfrac{1}{5}-dfrac{1}{3}xxd)2x(3xx
+dfrac{3}{4})+dfrac{4}{5}dfrac{1}{2}-2xx
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Tìm x, biết
a)\(\dfrac{1}{2}\)x\(x\)-\(\dfrac{7}{3}\)=\(\dfrac{-5}{6}\)+\(\dfrac{3}{4}\)x\(x\)
b)\(\dfrac{4}{5}\)x\(x\)-\(\dfrac{6}{5}\)=\(\dfrac{1}{2}\)+\(\dfrac{3}{2}\)x\(x\)
c)\(\dfrac{2}{5}\)x(3x\(x\)+\(\dfrac{3}{4}\))=\(1\dfrac{1}{5}\)-\(\dfrac{1}{3}\)x\(x\)
d)2x(3x\(x \)+\(\dfrac{3}{4}\))+\(\dfrac{4}{5}\)=\(\dfrac{1}{2}\)-2x\(x\)