Thực hiện phép tính: 2x ^2 y^4 + 3/ 2xy^5 - 3/ 2xy^5
Giải thích
a) \(\frac{{2{x^2}{y^4} + 3}}{{2x{y^5}}} - \frac{3}{{2x{y^5}}}\) \( = \frac{{2{x^2}{y^4} + 3 - 3}}{{2x{y^5}}}\) \( = \frac{{2{x^2}{y^4}}}{{2x{y^5}}} = \frac{x}{y}.\) | b) \(\frac{{{x^2} - 4}}{{x + 3}}:\frac{{{x^2} + 4x + 4}}{{2x + 6}}\) \( = \frac{{\left( {x - 2} \right)\left( {x + 2} \right)}}{{x + 3}}:\frac{{{{\left( {x + 2} \right)}^2}}}{{2\left( {x + 3} \right)}}\) \( = \frac{{\left( {x - 2} \right)\left( {x + 2} \right)}}{{x + 3}} \cdot \frac{{2\left( {x + 3} \right)}}{{{{\left( {x + 2} \right)}^2}}}\) \( = \frac{{2\left( {x - 2} \right)}}{{x + 2}}.\) |