Tìm giá trị của x , biết: (a) 2 x − 1 = 7 . (b) x − 1/2 = − 3/4 .

a) \(2x - 1 = 7\)

\(2x = 7 + 1\)

\(2x = 8\)

\(x = 8:2\)

\(x = 4\)

Vậy \(x = 4\).

b) \(x - \frac{1}{2} = \frac{{ - 3}}{4}\)

\(x = \frac{{ - 3}}{4} + \frac{1}{2}\)

\(x = \frac{{ - 1}}{4}\)

Vậy \(x = \frac{{ - 1}}{4}\).

c) \(\frac{{x - 2}}{6} = \frac{4}{3}\)

\(3\left( {x - 2} \right) = 4.6\)

\(3\left( {x - 2} \right) = 24\)

\(x - 2 = 24:3\)

\(x - 2 = 8\)

\(x = 8 + 2\)

\(x = 10\)

Vậy \(x = 10\).