Question

1,Tìm x,biết

a,\(\left(-1\dfrac{3}{5}+x\right)\div\dfrac{12}{13}=2\dfrac{1}{6}\)

b,\(\dfrac{-4}{7}x+\dfrac{7}{5}=\dfrac{1}{8}\div\left(-1\dfrac{2}{3}\right)\)

Answer 1

a) \(\left(-1\dfrac{3}{5}+x\right):\dfrac{12}{13}=2\dfrac{1}{6}\)

⇔ \(\left(\dfrac{-8}{5}+x\right).\dfrac{13}{12}=\dfrac{13}{6}\)

⇔ \(-\dfrac{8}{5}+x=\dfrac{13}{6}:\dfrac{13}{12}\)

⇔ \(-\dfrac{8}{5}+x=2\)

⇔ \(x=2+\dfrac{8}{5}\)

⇔ \(x=\dfrac{18}{5}\)

b) \(\dfrac{-4}{7}x+\dfrac{7}{5}=\dfrac{1}{8}:\left(-1\dfrac{2}{3}\right)\)

⇔ \(-\dfrac{4}{7}x+\dfrac{7}{5}=-\dfrac{3}{40}\)

⇔ \(-\dfrac{4}{7}x=-\dfrac{3}{40}-\dfrac{7}{5}\)

⇔ \(-\dfrac{4}{7}x=-\dfrac{59}{40}\)

⇔ \(x=\left(-\dfrac{59}{40}\right):\left(-\dfrac{4}{7}\right)\)

⇔ \(x=\dfrac{413}{160}\)

Answer 2

a, \(\left(-1\dfrac{3}{5}+x\right):\dfrac{12}{13}=2\dfrac{1}{6}\)

=> \(\left(-1\dfrac{3}{5}+x\right):\dfrac{12}{13}=\dfrac{13}{6}\)

=> \(\left(-1\dfrac{3}{5}+x\right)=\dfrac{13}{6}.\dfrac{12}{13}\)

=> \(\left(-1\dfrac{3}{5}+x\right)=2\)

=> \(\dfrac{-8}{5}+x=2\)

=> x= \(2+\dfrac{8}{5}=\dfrac{10}{5}+\dfrac{8}{5}\)

=> x= \(\dfrac{18}{5}\)