`x/4 - 3/7 + 2/5 = 31/140`
`x/4 - 3/7 = 31/140 - 2/5`
`x/4 - 3/7 = (-5)/28`
`x/4 = (-5)/28 + 3/7`
`x/4 = 1/4`
`=> x = 1/4 xx 4`
`x = 1`
Đúng 1
Bình luận (2)
Các câu hỏi tương tự
Tìm x ϵ Z, biết: dfrac{5}{17}+dfrac{-4}{9}+-dfrac{20}{31}+dfrac{12}{17}+dfrac{-11}{-31} dfrac{x}{9} ≤ dfrac{-3}{7}+dfrac{7}{15}+dfrac{4}{-7}+dfrac{8}{15}+dfrac{2}{3}
Đọc tiếp
Tìm x ϵ Z, biết:
\(\dfrac{5}{17}\)+\(\dfrac{-4}{9}\)+-\(\dfrac{20}{31}\)+\(\dfrac{12}{17}\)+\(\dfrac{-11}{-31}\)< \(\dfrac{x}{9}\) ≤ \(\dfrac{-3}{7}\)+\(\dfrac{7}{15}\)+\(\dfrac{4}{-7}\)+\(\dfrac{8}{15}\)+\(\dfrac{2}{3}\)
a)dfrac{2}{3}x-1dfrac{3}{2}b)| 5x - dfrac{1}{2}| - dfrac{2}{7} 25%c)dfrac{x-3}{4}dfrac{16}{x-3}d)dfrac{-8}{13}+dfrac{7}{17}+dfrac{21}{31}x≤dfrac{-9}{14}+4+dfrac{5}{-14}(xϵZ)
Đọc tiếp
a)\(\dfrac{2}{3}\)x-1=\(\dfrac{3}{2}\)
b)| 5x - \(\dfrac{1}{2}\)| - \(\dfrac{2}{7}\)= 25%
c)\(\dfrac{x-3}{4}\)=\(\dfrac{16}{x-3}\)
d)\(\dfrac{-8}{13}\)+\(\dfrac{7}{17}+\dfrac{21}{31}\)<x≤\(\dfrac{-9}{14}\)+4+\(\dfrac{5}{-14}\)(xϵZ)
1)\(\dfrac{1}{2}+\dfrac{13}{19}-\dfrac{4}{9}+\dfrac{6}{19}+\dfrac{5}{18}\)
2)\(\dfrac{ }{\dfrac{-20}{23}+\dfrac{2}{3}-\dfrac{3}{23}+\dfrac{2}{5}+\dfrac{7}{15}}\)
3)\(\dfrac{ }{\dfrac{4}{3}+\dfrac{-11}{31}+\dfrac{3}{10}-\dfrac{20}{31}-\dfrac{2}{5}}\)
4)\(\dfrac{ }{\dfrac{5}{7}.\dfrac{5}{11}+\dfrac{5}{7}.\dfrac{2}{11}-\dfrac{5}{7}.\dfrac{14}{11}}\)
Bài3:Tìm x
a,\(\dfrac{x}{7}\)=\(\dfrac{6}{12}\) b,\(\dfrac{-5}{x}\)=\(\dfrac{20}{28}\) c,\(\dfrac{x-2}{8}\)=\(\dfrac{3}{4}\) d,\(\dfrac{x}{-5}\)=\(\dfrac{-5}{x}\)
các ban giúp mình nha, cảm ơn các bạn
\(P=\dfrac{2-\dfrac{1}{3}+\dfrac{1}{4}}{2+\dfrac{1}{6}-\dfrac{1}{4}}\)
\(Q=\dfrac{3+\dfrac{1}{6}-\dfrac{2}{5}}{5-\dfrac{1}{6}+\dfrac{7}{10}}\)
cái này chắc các thầy cô hoặc các CVT làm được thôi,nó khó lắm
a, x =\(\dfrac{-2}{7}\) +\(\dfrac{9}{7}\)
b,\(\dfrac{x}{3}\) =\(\dfrac{2}{5}\) +\(\dfrac{-4}{3}\)
Làm giúp mik vs mình đang cần gấp!
Tìm x, biết:
a) dfrac{-2}{5} + dfrac{4}{5} . x dfrac{3}{5}
b) dfrac{-3}{7} - dfrac{4}{7} : x dfrac{2}{5}
c) dfrac{4}{7} . x + dfrac{2}{3} dfrac{-1}{5}
d) dfrac{5}{7} : x -1 dfrac{2}{3}
Đọc tiếp
Tìm x, biết:
a) \(\dfrac{-2}{5}\) + \(\dfrac{4}{5}\) . x = \(\dfrac{3}{5}\)
b) \(\dfrac{-3}{7}\) - \(\dfrac{4}{7}\) : x = \(\dfrac{2}{5}\)
c) \(\dfrac{4}{7}\) . x + \(\dfrac{2}{3}\) = \(\dfrac{-1}{5}\)
d) \(\dfrac{5}{7}\) : x -1 = \(\dfrac{2}{3}\)
Tìm x, biết:
a) dfrac{2}{5} + dfrac{3}{4}: x dfrac{-1}{2}
b) dfrac{5}{7} - dfrac{2}{3} . x dfrac{4}{5}
c) dfrac{1}{2} x + dfrac{2}{3} x dfrac{-2}{3}
d) dfrac{4}{7}x - x dfrac{-9}{14}
Đọc tiếp
Tìm x, biết:
a) \(\dfrac{2}{5}\) + \(\dfrac{3}{4}\): x = \(\dfrac{-1}{2}\)
b) \(\dfrac{5}{7}\) - \(\dfrac{2}{3}\) . x = \(\dfrac{4}{5}\)
c) \(\dfrac{1}{2}\) x + \(\dfrac{2}{3}\) x = \(\dfrac{-2}{3}\)
d) \(\dfrac{4}{7}\)x - x= \(\dfrac{-9}{14}\)
1.Thực hiện các phép tính sau :
a) \(-\dfrac{4}{3}.\dfrac{5}{12}+\dfrac{1}{3}.\dfrac{5}{12}\) b)\(3\dfrac{1}{5}+\left(\dfrac{2}{7}-\dfrac{7}{2}\right):\dfrac{3}{28}\)
2.Tìm x, biết:
a) 2x+19=\(^{5^2}\) b)\(-\dfrac{2}{9}x-\dfrac{1}{7}=\dfrac{4}{21}\)
Tìm x biết: a) x + \(\dfrac{2}{3}=\dfrac{4}{27}\) b) \(\dfrac{3}{4}x-\dfrac{7}{3}=\dfrac{1}{4}x+\dfrac{1}{6}\)
c) \(\dfrac{13}{10}x-\dfrac{5}{2}=\dfrac{7}{2}\) d) (3\(x\) + 2) \(\left(\dfrac{-2}{5}x-7\right)=0\)