giải chi tiết ạ
4 : 3/4 + 1/5 x 3/7
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
2/3 x X = 1/4 X x 1/5 = 1/2 X : 7/8 = 2/3
X = 1/4 : 2/3 X = 1/2 : 1/5 X = 2/3 x 7/8
X = 3/8 X = 5/2 X = 7/12
chúc bạn học tôt
`4 1/2 xx x - 2 1/2 xx x = 1 1/2`
`=> 9/2 xx x - 5/2 xx x = 3/2`
`=> (9/2-5/2)xx x=3/2`
`=>4/2xx x=3/2`
`=>x=3/2:4/2`
`=>x=3/2:2`
`=>x=3/2xx1/2`
`=>x=3/4`
Vậy `x=3/4`
__
`x xx1/2+x xx1/3=5/6`
`=>x xx(1/2+1/3)=5/6`
`=>x xx(3/6+2/6)=5/6`
`=>x xx5/6=5/6`
`=>x=5/6:5/6`
`=>x=5/6xx6/5`
`=>x=1`
a: \(\Leftrightarrow\left[{}\begin{matrix}3x+2=4\\3x+2=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{2}{3}\\x=-2\end{matrix}\right.\)
a) \(x=-\dfrac{3}{5}\times\dfrac{9}{7}=-\dfrac{27}{35}\)
b) \(x\left(0,4-\dfrac{1}{5}\right)=\dfrac{3}{4}\)
\(x=\dfrac{3}{4}:\dfrac{1}{5}=\dfrac{15}{4}\)
a, \(x=-3,5.\dfrac{9}{7}=-\dfrac{9}{2}\)
b, \(\dfrac{2}{5}x-\dfrac{1}{5}x=\dfrac{3}{4}\Leftrightarrow\dfrac{1}{5}x=\dfrac{3}{4}\Leftrightarrow x=\dfrac{3}{4}:\dfrac{1}{5}=\dfrac{15}{4}\)
\(\frac{4}{7}+x\times2=\frac{5}{3}\)
\(x\times2=\frac{5}{3}-\frac{4}{7}\)
\(x\times2=\frac{23}{21}\)
\(x=\frac{23}{21}:2\)
\(x=\frac{23}{42}\)
\(\frac{4}{7}+x\times2=\frac{5}{3}\)
\(x\times2=\frac{5}{3}-\frac{4}{7}\)
\(x\times2=\frac{23}{21}\)
\(x=\frac{23}{21}:2\)
\(x=\frac{23}{42}\)
Vậy x = 23/42
\(a,\left(\dfrac{31}{35}-\dfrac{4}{7}\right)\times\dfrac{8}{7}:2\\ =\left(\dfrac{31}{35}-\dfrac{4\times5}{35}\right)\times\dfrac{8}{7}:2\\ =\dfrac{11}{35}\times\dfrac{8}{7}:2\\ =\dfrac{88}{245}:2\\ =\dfrac{44}{245}\\ b,\left(1-\dfrac{1}{2}\right)\times\left(1-\dfrac{1}{3}\right)\times\left(1-\dfrac{1}{4}\right)\times\left(1-\dfrac{1}{5}\right)\\ =\left(\dfrac{2-1}{2}\right)\times\left(\dfrac{3-1}{3}\right)\times\left(\dfrac{4-1}{4}\right)\times\left(\dfrac{5-1}{5}\right)\\ =\dfrac{1}{2}\times\dfrac{2}{3}\times\dfrac{3}{4}\times\dfrac{4}{5}\\ =\dfrac{1}{3}\times\dfrac{3}{4}\times\dfrac{4}{5}\\ =\dfrac{1}{4}\times\dfrac{4}{5}=\dfrac{1}{5}\)
a, ( \(\dfrac{31}{35}\) - \(\dfrac{4}{7}\)) \(\times\) \(\dfrac{8}{7}\): 2
= \(\left(\dfrac{31}{35}-\dfrac{20}{35}\right)\) \(\times\) \(\dfrac{8}{7}\) : 2
= \(\dfrac{11}{35}\) \(\times\) \(\dfrac{8}{7}\) \(\times\) \(\dfrac{1}{2}\)
= \(\dfrac{44}{35}\) \(\times\) \(\dfrac{4}{7}\)
= \(\dfrac{44}{245}\)
b, ( 1 - \(\dfrac{1}{2}\)) \(\times\) ( 1 - \(\dfrac{1}{3}\)) \(\times\) ( 1 - \(\dfrac{1}{4}\)) \(\times\) ( 1 - \(\dfrac{1}{5}\))
= \(\dfrac{1}{2}\) \(\times\) \(\dfrac{2}{3}\) \(\times\) \(\dfrac{3}{4}\) \(\times\) \(\dfrac{4}{5}\)
= \(\dfrac{1}{5}\) \(\times\) \(\dfrac{2\times3\times4}{2\times3\times4}\)
= \(\dfrac{1}{5}\)
\(=4\cdot\dfrac{4}{3}+\dfrac{3}{35}=\dfrac{16}{3}+\dfrac{3}{35}=\dfrac{560}{105}+\dfrac{9}{105}=\dfrac{569}{105}\)
\(4\times\dfrac{4}{3}+\dfrac{1}{5}\times\dfrac{3}{7}=\dfrac{16}{3}+\dfrac{3}{35}=\dfrac{569}{105}\)