`x-8/17 . (-68/5) = 3/7`
`x-(-32)/5 = 3/7`
`x+32/5 = 3/7`
`x=3/7 - 32/5`
`x=15/35 - 224/35`
`x=-209/35`
Vậy `x=-209/35`
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`-5/6 . 78/25 + x = 4/15 . (-3)/8`
`-5/6 . 78/25 + x = -1/10`
`(-5xx78)/(6xx25) + x = -1/10`
`-13/5 + x = -1/10`
`x=-1/10 - (-13/5)`
`x=-1/10 + 13/5`
`x=5/2`
Vậy `x=5/2`
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`21xx 33/14 - x = -16/2`
`21 . 33/14 - x = -8`
`99/2 - x = -8`
`x=99/2 - (-8)`
`x=99/2 + 8`
`x=115/2`
Vậy `x=115/2`
___________________________
`3/4 . 7/9 + 1/4 . 7/9 -x=1`
`[7/9 . (3/4 + 1/4) ] -x=1`
`[7/9 . 4/4] - x=1`
`7/9 . 1 - x=1`
`7/9 - x=1`
`x=7/9-1`
`x=7/9-9/9`
`x=-2/9`
Vậy `x=-2/9`
\(k,x-\dfrac{8}{17}.\left(\dfrac{-68}{5}\right)=\dfrac{3}{7}\)
\(x-\dfrac{-32}{5}=\dfrac{3}{7}\)
\(x=\dfrac{3}{7}+\dfrac{-32}{5}\)
\(x=\dfrac{-209}{35}\)
\(l,\dfrac{-5}{6}.\dfrac{78}{25}+x=\dfrac{4}{15}.\dfrac{-3}{8}\)
\(\dfrac{-13}{5}+x=\dfrac{-1}{10}\)
\(x=\dfrac{-1}{10}-\dfrac{-13}{5}\)
\(x=\dfrac{5}{2}\)
\(m,21.\dfrac{33}{14}-x=\dfrac{-16}{2}\)
\(\dfrac{99}{2}-x=\dfrac{-16}{2}\)
\(x=\dfrac{99}{2}-\dfrac{-16}{2}\)
\(x=\dfrac{115}{2}\)
\(n,\dfrac{3}{4}.\dfrac{7}{9}+\dfrac{1}{4}.\dfrac{7}{9}-x=1\)
\(\dfrac{7}{9}.\left(\dfrac{3}{4}+\dfrac{1}{4}\right)-x=1\)
\(\dfrac{7}{9}.1-x=1\)
\(\dfrac{7}{9}-x=1\)
\(x=\dfrac{7}{9}-1\)
\(x=\dfrac{-2}{9}\)
\(k.x-\dfrac{8}{17}\cdot\left(-\dfrac{68}{5}\right)=\dfrac{3}{7}\)
\(x+\dfrac{8}{17}\cdot\dfrac{68}{5}=\dfrac{3}{7}\)
\(x+\dfrac{32}{5}=\dfrac{3}{7}\)
\(x=\dfrac{3}{7}-\dfrac{32}{5}\)
\(x=-\dfrac{209}{35}.\)
\(Vậy...\)
\(l.-\dfrac{5}{6}\cdot\dfrac{78}{25}+x=\dfrac{4}{15}\cdot\dfrac{-3}{8}\)
\(\dfrac{-13}{5}+x=\dfrac{1}{15}\cdot\dfrac{-3}{2}\)
\(-\dfrac{13}{5}+x=-\dfrac{3}{30}\)
\(-\dfrac{13}{5}+x=-\dfrac{1}{10}\)
\(x=-\dfrac{1}{10}+\dfrac{13}{5}\)
\(x=\dfrac{5}{2}.\)
\(Vậy...\)
\(m.21\cdot\dfrac{33}{14}-x=-\dfrac{16}{2}\)
\(\dfrac{99}{2}-x=-\dfrac{16}{2}\)
\(\dfrac{99}{2}-x=-8\)
\(-x=-8-\dfrac{99}{2}\)
\(-x=-\dfrac{115}{2}\)
\(x=\dfrac{115}{2}.\)
\(Vậy...\)
\(n.\dfrac{3}{4}\cdot\dfrac{7}{9}+\dfrac{1}{4}\cdot\dfrac{7}{9}-x=1\)
\(-x+\dfrac{7}{9}=1\)
\(-x=1-\dfrac{7}{9}\)
\(-x=\dfrac{2}{9}\)
\(x=\dfrac{2}{9}\)
\(Vậy...\)
