a)    \(x - {1 \over 4} = {5 \over 8}.{2 \over 3} \)

\(x - {1 \over 4} = {5 \over {12}} \)

\(x\,\,\,\,\,\,\,\,\,\, = {5 \over {12}} + {1 \over 4} \)

\(x\,\,\,\,\,\,\,\,\,\, = {8 \over {12}} = {2 \over 3}\)

b)    \({x \over {126}} = {{ - 5} \over 9}.{4 \over 7} \)

\({x \over {126}} = {{ - 20} \over {63}} \)

\(63.x = - 20.126 \)

\(x = {{ - 20.126} \over {63}} \)

\(x = - 40\)