`x/5=(x+2)/7`
`=>x*7=(x+2)*5`
`=>7x=5x+10`
`=>7x-5x=10`
`=>2x=10`
`=>x=5`
\(\dfrac{x}{5}\) = \(\dfrac{x+2}{7}\)
= \(\dfrac{5}{5}\) = \(\dfrac{5+2}{7}\)
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) \(x:\dfrac{6}{13}=\dfrac{13}{7}\) b) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\) c) \(\left(\dfrac{3}{10}-x\right):\dfrac{2}{5}=\dfrac{3}{5}\) d) \(\dfrac{2}{3}.x-\dfrac{7}{6}=\dfrac{5}{2}\)
Tìm x:
a) \(\dfrac{-3}{7}\).x=\(\dfrac{3}{56}\).\(\dfrac{28}{9}\)
b) x-\(\dfrac{3}{16}\)=\(\dfrac{7}{15}\):\(\dfrac{3}{5}\)
c) \(\dfrac{2}{5}\)+\(\dfrac{1}{5}\).x=\(\dfrac{5}{6}\)
d) \(\dfrac{3}{4}\)x-\(\dfrac{2}{5}\)x=\(\dfrac{3}{7}\).\(\dfrac{1}{6}\)+\(\dfrac{5}{7}\).\(\dfrac{1}{6}\)
*Lưu ý: Trình bày chi tiết kết quả.
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= \(\dfrac{-9}{14}\)
a) x + \(\dfrac{2}{5}\) = \(\dfrac{1}{2}\)
b) x - \(\dfrac{2}{5}\) = \(\dfrac{2}{7}\)
c) \(\dfrac{3}{5}\) - x = \(\dfrac{1}{10}\)
d) x . \(\dfrac{3}{4}\) = \(\dfrac{9}{20}\)
e) x : \(\dfrac{1}{7}\) = 14
f) ( \(\dfrac{1}{4}\) + x ) . \(\dfrac{1}{2}\) = \(\dfrac{2}{5}\)
g) x . \(\dfrac{2}{3}\) - \(\dfrac{2}{3}\) = \(\dfrac{9}{12}\)
h) \(\dfrac{3}{4}\) + \(\dfrac{1}{4}\) : x = \(\dfrac{2}{5}\)
k) \(3\dfrac{4}{5}\) - x = \(\dfrac{18}{5}\)
l) x . \(2\dfrac{1}{3}\) = \(\dfrac{3}{4}\)
m) x . \(\dfrac{6}{11}\) + x . \(\dfrac{5}{11}\) = 2025
n) x . \(\dfrac{14}{9}\) - x . \(\dfrac{7}{9}\) + x . \(\dfrac{5}{9}\) = 2
Các bạn làm theo cách bình thường ở lớp 5 cho mính nhé!
Chú ý: dấu "." là dấu nhân.
1/ (\(\left(-\dfrac{2}{3}\right)\)\(^2\) x \(\dfrac{-9}{8}\) - 25% x \(\dfrac{-16}{5}\)
2/ -1\(\dfrac{2}{5}\) x 75% + \(\dfrac{-7}{5}\) x 25%
3/ -2\(\dfrac{3}{7}\) x (-125%) + \(\dfrac{-17}{7}\) x 25%
4/ (-2)\(^3\) x (\(\dfrac{3}{4}\) x 0.25) : (2\(\dfrac{1}{4}\) - 1\(\dfrac{1}{6}\))
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) \(\left(\dfrac{-2}{5}x-7\right)=0\)
a) \(\dfrac{2}{7}-\dfrac{8}{9}.x=\dfrac{2}{3}\)
b) \(\dfrac{2}{5}-\dfrac{2}{5}x=\dfrac{2}{5}\)
c) \(\dfrac{2}{9}-\dfrac{7}{8}x=\dfrac{1}{3}\)
\(\dfrac{x}{2}\)-(\(\dfrac{3.x}{5}\)-\(\dfrac{13}{5}\))=\(\dfrac{7}{5}\)+\(\dfrac{7}{10}\)x
\(\dfrac{-5}{7}\)x\(\dfrac{2}{11}\)+\(\dfrac{-5}{7}\)x\(\dfrac{9}{11}\)+\(\dfrac{5}{7}\)
