Краткий ответ
а) \(a^{15}y^{15}\);
б) \(x^{21}\);
в) \(\dfrac{25}{36}x^2y^2\);
г) \(b^{60}\).а) \((ab)^{12}\);
б) \((2x)^5\);
в) \(\left(\dfrac45a^4b\right)^2\).\[ \boxed{\text{А–3,\ Б–1,\ В–2}} \]
а) \(10\,000\,000\);
б) \(25\,000\);
в) \(25\).
Ключевые шаги
Используем свойства степеней:
\[ (uv)^n=u^nv^n,\qquad (u^m)^n=u^{mn},\qquad u^m\cdot u^n=u^{m+n}. \]
1.
\[ (ay)^{15}=a^{15}y^{15} \]
\[ (x^7)^3=x^{7\cdot3}=x^{21} \]
\[ \left(-\frac56xy\right)^2= \left(-\frac56\right)^2x^2y^2= \frac{25}{36}x^2y^2 \]
\[ \bigl((b^4)^3\bigr)^5=b^{4\cdot3\cdot5}=b^{60} \]
2.
\[ a^{12}b^{12}=(ab)^{12} \]
Так как \(32=2^5\), то
\[ 32x^5=2^5x^5=(2x)^5. \]
\[ \frac{16}{25}a^8b^2 =\left(\frac45\right)^2(a^4)^2b^2 =\left(\frac45a^4b\right)^2. \]
3.
\[ \text{А: }(x^5)^8=x^{40}\Rightarrow 3 \]
\[ \text{Б: }(b^7)^3\cdot b^4=b^{21+4}=b^{25}\Rightarrow 1 \]
\[ \text{В: }(b^9)^5\cdot(b^3)^6=b^{45+18}=b^{63}\Rightarrow 2 \]
4.
\[ 25^7\cdot0{,}4^7=(25\cdot0{,}4)^7=10^7=10\,000\,000 \]
\[ 4^4\cdot2{,}5^5 =256\cdot\left(\frac52\right)^5 =256\cdot\frac{3125}{32}=25\,000 \]
\[ \frac{5^8\cdot(5^4)^6}{5^{28}\cdot25} =\frac{5^{8+24}}{5^{28+2}} =5^2=25. \]
