Thu gọn mỗi đơn thức sau:

a) $\frac{{ - 9}}{{17}}{x^{23}}{y^{22}}{y^{14}}$.

b) $\frac{2}{{\sqrt {121} }}x{y^3}z{y^2}{z^3}$.

c) $\frac{{ - 187}}{{124}}{x^4}{y^6}{z^8}{x^5}{y^2}{z^{10}}$.

Lời giải

a) $\frac{{ - 9}}{{17}}{x^{23}}{y^{22}}{y^{14}} = \frac{{ - 9}}{{17}}{x^{23}}\left( {{y^{22}}.{y^{14}}} \right) = \frac{{ - 9}}{{17}}{x^{23}}{y^{36}}$.

b) $\frac{2}{{\sqrt {121} }}x{y^3}z{y^2}{z^3} = \frac{2}{{\sqrt {{{11}^2}} }}x\left( {{y^3}.{y^2}} \right)\left( {z.{z^3}} \right) = \frac{2}{{11}}x{y^5}{z^4}$.

c) $\frac{{ - 187}}{{124}}{x^4}{y^6}{z^8}{x^5}{y^2}{z^{10}} = \frac{{ - 187}}{{124}}\left( {{x^4}.{x^5}} \right)\left( {{y^6}.{y^2}} \right)\left( {{z^8}.{z^{10}}} \right) = \frac{{ - 187}}{{124}}{x^9}{y^8}{z^{18}}$.