Tìm (x), biết:

a) \(8 - 2x =  - 4\)

\(2x = 8 - \left( { - 4} \right)\)

\(2x = 12\)

\(x = 6\)

Vậy \(x = 6\).

b) \(928 - \left( {31 + x} \right) = 128\)

\(31 + x = 928 - 128\)

\(31 + x = 800\)

\(x = 800 - 31\)

\(x = 769\)

Vậy \(x = 769\).

c) \[584 - {\left( {x - 1} \right)^3} =  - 416\]

\[{\left( {x - 1} \right)^3} = 584 - \left( { - 416} \right)\]

\[{\left( {x - 1} \right)^3} = 1000\]

\(x - 1 = 10\)

\(x = 11\)

Vậy \(x = 11\).