Question

Thực hiện các phép tính:

\(a)\frac{{3 - 2{\rm{x}}}}{{x - 1}} - \frac{{2 + 5{\rm{x}}}}{{x - 1}}\)

\(b)\frac{1}{{4{{\rm{x}}^2}y}} - \frac{1}{{6{\rm{x}}{y^2}}}\)

Answer 1

\(a)\frac{{3 - 2{\rm{x}}}}{{x - 1}} - \frac{{2 + 5{\rm{x}}}}{{x - 1}} = \frac{{3 - 2{\rm{x}} - \left( {2 + 5{\rm{x}}} \right)}}{{x - 1}} = \frac{{3 - 2{\rm{x}} - 2 - 5{\rm{x}}}}{{x - 1}} = \frac{{1 - 7{\rm{x}}}}{{x - 1}}\)

\(b)\frac{1}{{4{{\rm{x}}^2}y}} - \frac{1}{{6{\rm{x}}{y^2}}} = \frac{{3y}}{{12{{\rm{x}}^2}y{}^2}} - \frac{{2{\rm{x}}}}{{12{{\rm{x}}^2}{y^2}}} = \frac{{3y - 2{\rm{x}}}}{{12{{\rm{x}}^2}{y^2}}}\)