Đáp án:
d) \(HS:\dfrac{7}{{20}}{a^3}\)
Giải thích các bước giải:
\(\begin{array}{l}
B3:\\
a)\dfrac{5}{4}.1.{\left( {\dfrac{5}{2}} \right)^2}.{x^{2 + 2}}.{y^{1 + 2}}\\
= \dfrac{{125}}{{16}}{x^4}{y^3}\\
\to HS:\dfrac{{125}}{{16}}\\
Biến:{x^4}{y^3}\\
Bậc:4 + 3 = 7\\
c) - \dfrac{3}{{25}}.\left( { - \dfrac{1}{9}} \right).\dfrac{{25}}{4}.{x^{1 + 4}}.{y^{2 + 6}}\\
= \dfrac{1}{{12}}{x^5}{y^8}\\
\to HS:\dfrac{1}{{12}}\\
Biến:{x^5}{y^8}\\
Bậc:5 + 8 = 13\\
b)\left( { - 2} \right).\left( { - 27} \right).{x^{2 + 6}}.{y^{1 + 6}}.{z^3}\\
= 54{x^8}{y^7}{z^3}\\
\to HS:54\\
Biến:{x^8}{y^7}{z^3}\\
Bậc:8 + 7 + 3 = 18\\
d)\dfrac{1}{4}.\dfrac{7}{5}.{a^3}.{x^{6 + 5}}.{y^{2 + 3}}\\
= \dfrac{7}{{20}}{a^3}{x^{11}}{y^5}\\
\to HS:\dfrac{7}{{20}}{a^3}\\
Biến:{x^{11}}{y^5}\\
Bậc:11 + 5 = 16
\end{array}\)
