Tìm x biết: 3/7 - 4/7 : (x - 1) = 5/7
Tìm x biết: \(\frac{3}{7} - \frac{4}{7}:\left( {x - 1} \right) = \frac{5}{7}\).
Tìm x biết: \(\frac{3}{7} - \frac{4}{7}:\left( {x - 1} \right) = \frac{5}{7}\).
\(\frac{3}{7} - \frac{4}{7}:\left( {x - 1} \right) = \frac{5}{7}\)
⇔ \(\frac{4}{7}:\left( {x - 1} \right) = \frac{3}{7} - \frac{5}{7} = \frac{{ - 2}}{7}\)
⇔ \(x - 1 = \frac{4}{7}:\frac{{ - 2}}{7}\)
⇔ x – 1 = –2
⇔ x = – 2 + 1
⇔ x = –1
Vậy x = –1.