\(\dfrac{3}{7}+\dfrac{1}{7}:x=\dfrac{3}{14}\)
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
H
10 tháng 5 2023
`7 xx 3/14 -1/14`
`= 21/14 -1/14`
`= 20/14`
`=10/7`
__
`3/2 + 7/4 xx 2/5`
`= 3/2 + 14/20`
`= 3/2 + 7/10`
`= 15/10 +7/10`
`= 23/10`
__
`9/8 : 3 + 7/3 : 3`
`= 9/8 xx 1/3 + 7/3 xx 1/3`
`=1/3 xx ( 9/8 + 7/3)`
`= 1/3 xx 83/24`
`= 83/72`
__
`2 : 3/4 - 5/8 xx 4/3`
`= 2 xx 4/3 - 5/8 xx 4/3`
`= 4/3 xx ( 2-5/8)`
`= 4/3 xx ( 16/8 -5/8)`
`= 4/3 xx 11/8`
`= 44/24`
`=11/6`
` @ \color{Red}{sushiteam}`
17 tháng 7 2021
a) Ta có: \(\dfrac{2}{3}x-1=\dfrac{3}{2}\)
\(\Leftrightarrow x\cdot\dfrac{2}{3}=\dfrac{5}{2}\)
hay \(x=\dfrac{5}{2}:\dfrac{2}{3}=\dfrac{5}{2}\cdot\dfrac{3}{2}=\dfrac{15}{4}\)
b) Ta có: \(\left|5x-\dfrac{1}{2}\right|-\dfrac{2}{7}=25\%\)
\(\Leftrightarrow\left|5x-\dfrac{1}{2}\right|=\dfrac{1}{4}+\dfrac{2}{7}=\dfrac{15}{28}\)
\(\Leftrightarrow\left[{}\begin{matrix}5x-\dfrac{1}{2}=\dfrac{15}{28}\\5x-\dfrac{1}{2}=\dfrac{-15}{28}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}5x=\dfrac{29}{28}\\5x=\dfrac{-1}{28}\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{29}{140}\\x=\dfrac{-1}{140}\end{matrix}\right.\)
17 tháng 7 2021
c) Ta có: \(\dfrac{x-3}{4}=\dfrac{16}{x-3}\)
\(\Leftrightarrow\left(x-3\right)^2=64\)
\(\Leftrightarrow\left[{}\begin{matrix}x-3=8\\x-3=-8\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=11\\x=-5\end{matrix}\right.\)
d) Ta có: \(\dfrac{-8}{13}+\dfrac{7}{17}+\dfrac{21}{31}\le x\le\dfrac{-9}{14}+4-\dfrac{5}{14}\)
\(\Leftrightarrow\dfrac{3246}{6851}\le x\le3\)
\(\Leftrightarrow x\in\left\{1;2;3\right\}\)
8 tháng 3 2022
b: \(\Leftrightarrow\left(x-\dfrac{1}{2}\right):\dfrac{1}{3}=9+\dfrac{5}{7}-\dfrac{5}{7}=9\)
=>x-1/2=27
hay x=55/2
c: =>1/2x-3/4=42/63=2/3
=>1/2x=17/12
hay x=17/6
10 tháng 9 2021
\(B=\dfrac{1+\dfrac{1}{7}+\dfrac{1}{7^2}-\dfrac{1}{7^3}}{4+\dfrac{4}{7}+\dfrac{4}{7^2}-\dfrac{4}{7^3}}\cdot\dfrac{858585}{313131}\cdot\left(-1\dfrac{14}{17}\right)\)
\(=\dfrac{1}{4}\cdot\dfrac{85}{31}\cdot\dfrac{-31}{17}\)
\(=\dfrac{-5}{4}\)
9 tháng 5 2022
a) \(\dfrac{x}{y}\times\dfrac{3}{4}=\dfrac{5}{6}+\dfrac{1}{3}\)
\(\dfrac{x}{y}\times\dfrac{3}{4}=\dfrac{7}{6}\)
\(\dfrac{x}{y}=\dfrac{7}{6}:\dfrac{3}{4}\)
\(\dfrac{x}{y}=\dfrac{14}{9}\)
b) \(\dfrac{7}{9}:\dfrac{x}{y}=\dfrac{10}{7}-\dfrac{13}{14}\)
\(\dfrac{7}{9}:\dfrac{x}{y}=\dfrac{1}{2}\)
\(\dfrac{x}{y}=\dfrac{7}{9}:\dfrac{1}{2}\)
\(\dfrac{x}{y}=\dfrac{14}{9}\)
C
17 tháng 5 2022
\(4+\dfrac{3}{5}=\dfrac{20}{5}+\dfrac{3}{5}=\dfrac{23}{5}\)
\(\dfrac{1}{5}+\dfrac{2}{7}=\dfrac{7}{35}+\dfrac{10}{35}=\dfrac{17}{35}\)
\(\dfrac{4}{7}\times\dfrac{14}{3}=\dfrac{56}{21}=\dfrac{8}{3}\)
\(\dfrac{5}{6}:\dfrac{4}{9}=\dfrac{5}{6}\times\dfrac{9}{4}=\dfrac{15}{8}\)
O
17 tháng 5 2022
\(4+\dfrac{3}{5}=\dfrac{20}{5}+\dfrac{3}{5}=\dfrac{23}{5}\)
\(\dfrac{1}{5}+\dfrac{2}{7}=\dfrac{7}{35}+\dfrac{5}{35}=\dfrac{12}{35}\)
\(\dfrac{4}{7}\times\dfrac{14}{3}=\dfrac{56}{21}=\dfrac{8}{3}\)
\(\dfrac{5}{6}:\dfrac{4}{9}=\dfrac{5}{6}\times\dfrac{9}{4}=\dfrac{15}{8}\)
NT
Nguyễn Thị Thương Hoài
Giáo viên
VIP
5 tháng 8 2023
a, \(\dfrac{7}{8}\) \(\times\) \(\dfrac{3}{13}\) + \(\dfrac{4}{9}\) \(\times\) \(\dfrac{4}{13}\)
= \(\dfrac{1}{13}\) \(\times\)( \(\dfrac{21}{8}\) + \(\dfrac{16}{9}\))
= \(\dfrac{1}{13}\) \(\times\)( \(\dfrac{189}{72}\) + \(\dfrac{128}{72}\))
= \(\dfrac{1}{13}\) \(\times\) \(\dfrac{317}{73}\)
= \(\dfrac{317}{949}\)
b, \(\dfrac{6}{5}\) + \(\dfrac{7}{3}\) + \(\dfrac{8}{9}\)
= \(\dfrac{54}{45}\) + \(\dfrac{105}{45}\) + \(\dfrac{40}{45}\)
= \(\dfrac{199}{45}\)
c, 23 : \(\dfrac{5}{14}\) + \(\dfrac{6}{7}\) + \(\dfrac{4}{9}\)
= \(\dfrac{322}{5}\) + \(\dfrac{6}{7}\) + \(\dfrac{4}{9}\)
= \(\dfrac{20286}{315}\) + \(\dfrac{270}{315}\) + \(\dfrac{140}{315}\)
= \(\dfrac{20696}{315}\)
d, 4\(\dfrac{1}{4}\) + 7\(\dfrac{3}{7}\) - 2\(\dfrac{4}{17}\)
= 4 + \(\dfrac{1}{4}\) + 7 + \(\dfrac{3}{7}\) - 2 - \(\dfrac{4}{17}\)
= (4+7-2) + (\(\dfrac{1}{4}\) + \(\dfrac{3}{7}\) - \(\dfrac{4}{17}\))
= 9 + \(\dfrac{119}{476}\) + \(\dfrac{204}{476}\) - \(\dfrac{112}{476}\)
= 9\(\dfrac{211}{476}\) = \(\dfrac{4495}{476}\)
e, 8 - (9\(\dfrac{2}{11}\) + \(\dfrac{8}{33}\))
= 8 - 9 - \(\dfrac{2}{11}\) - \(\dfrac{8}{33}\)
= -1 - \(\dfrac{2}{11}\) - \(\dfrac{8}{33}\)
= \(\dfrac{-33}{33}\) - \(\dfrac{-6}{33}\) - \(\dfrac{8}{33}\)
= - \(\dfrac{47}{33}\)
27 tháng 8 2023
a, 2/5 + 3/4 : x = -1/2
3/4 : x = -1/2 - 2/5
3/4 : x = -9/10
x = 3/4 : -9/10
x = -5/6
27 tháng 8 2023
b, 5/7 - 2/3 . x = 4/5
2/3 . x = 4/5 + 5/7
2/3 . x = 53/35
x = 53/35 : 2/3
x = 159/70
\(\dfrac{3}{7}+\dfrac{1}{7}:x=\dfrac{3}{14}\)
⇒ \(\dfrac{1}{7}:x=\dfrac{3}{14}-\dfrac{3}{7}\)
⇒ \(\dfrac{1}{7}:x=\dfrac{-3}{14}\)
⇒ x= \(\dfrac{1}{7}:\dfrac{3}{14}\)
⇒ x=\(\dfrac{-2}{3}\)
\(\dfrac{3}{7}+\dfrac{1}{7}:x=\dfrac{3}{14} <=> \dfrac{6x+2-3x}{14x}=0 (*) điều kiện x khác 0 pt(*)<=>6x+2-3x=0<=>3x=-2<=>x=\dfrac{-2}{3} Vậy x = \dfrac{-2}{3}\)