Question

Tìm x, biết:

a)\(x + \frac{1}{2} =  - \frac{1}{3};\)          b)\(\left( { - \frac{2}{7}} \right) + x =  - \frac{1}{4}\)

Answer 1

a)

\(\begin{array}{l}x + \frac{1}{2} =  - \frac{1}{3}\\x =  - \frac{1}{3} - \frac{1}{2}\\x =  - \frac{2}{6} - \frac{3}{6}\\x = \frac{{ - 5}}{6}\end{array}\)     

Vậy \(x = \frac{{ - 5}}{6}\).

 b)

\(\begin{array}{l}\left( { - \frac{2}{7}} \right) + x =  - \frac{1}{4}\\x =  - \frac{1}{4} - \left( { - \frac{2}{7}} \right)\\x =  - \frac{1}{4} + \frac{2}{7}\\x =  - \frac{7}{{28}} + \frac{8}{{28}}\\x = \frac{1}{{28}}\end{array}\)

Vậy \(x = \frac{1}{{28}}\).