Краткие ответы:
- \(25\)
- \(49\)
- \(256\)
- \(625\)
- \(64\)
- \(4\)
- \(5\)
- \(320\)
- \(1{,}4\)
- \(310\)
- \(23{,}1\)
- \(3100\)
- \(30300\)
- \(4270\)
- \(120{,}5\)
Основные правила
\[ a^m\cdot a^n=a^{m+n},\qquad \frac{a^m}{a^n}=a^{m-n},\qquad (a^m)^n=a^{mn}. \]
Также \(a^{-n}=\dfrac1{a^n}\).
Решение
\[ \begin{aligned} 130)\quad &\frac{5^{-7}\cdot5^4}{5^{-5}} =5^{-7+4-(-5)} =5^2=25. \end{aligned} \]
\[ \begin{aligned} 132)\quad &\frac{7^{-6}\cdot7^3}{7^{-5}} =7^{-6+3-(-5)} =7^2=49. \end{aligned} \]
\[ \begin{aligned} 134)\quad &\frac{(16^{-2})^2}{16^{-6}} =\frac{16^{-4}}{16^{-6}} =16^{-4-(-6)} =16^2=256. \end{aligned} \]
\[ \begin{aligned} 136)\quad &5^8\cdot\frac{5^{-3}}5 =5^8\cdot5^{-3}\cdot5^{-1} =5^{8-3-1} =5^4=625. \end{aligned} \]
\[ \begin{aligned} 138)\quad &\frac{64^3}{4^4}:4^2 =\frac{(4^3)^3}{4^4}:4^2 =4^{9-4-2} =4^3=64. \end{aligned} \]
\[ \begin{aligned} 140)\quad &\frac{3^6\cdot4^7}{12^6} =\frac{3^6\cdot4^7}{(3\cdot4)^6} =\frac{3^6\cdot4^7}{3^6\cdot4^6} =4. \end{aligned} \]
В №142 \(0{,}2^5\) понимаем как \((0{,}2)^5\):
\[ \begin{aligned} 142)\quad &\frac{(0{,}2)^2}{(0{,}2)^{-2}}:(0{,}2)^5\\ &=(0{,}2)^{2-(-2)-5} =(0{,}2)^{-1} =\frac1{0{,}2}=5. \end{aligned} \]
\[ \begin{aligned} 144)\quad &7\cdot2^5+3\cdot2^5 =(7+3)\cdot2^5 =10\cdot32=320. \end{aligned} \]
\[ \begin{aligned} 146)\quad &\frac{0{,}7\cdot10^{-2}}{5\cdot10^{-3}} =\frac{0{,}7}{5}\cdot10^{-2-(-3)}\\ &=0{,}14\cdot10=1{,}4. \end{aligned} \]
\[ \begin{aligned} 148)\quad &54\cdot10-2{,}3\cdot10^2 =540-230=310. \end{aligned} \]
\[ \begin{aligned} 150)\quad &(11\cdot10^{-3})(2{,}1\cdot10^3)\\ &=11\cdot2{,}1\cdot10^0 =23{,}1. \end{aligned} \]
\[ \begin{aligned} 152)\quad &54\cdot10^2-2{,}3\cdot10^3 =5400-2300=3100. \end{aligned} \]
\[ \begin{aligned} 154)\quad &3{,}3\cdot10^3+2{,}7\cdot10^4\\ &=3300+27000=30300. \end{aligned} \]
\[ \begin{aligned} 156)\quad &7\cdot10+2\cdot10^2+4\cdot10^3\\ &=70+200+4000=4270. \end{aligned} \]
\[ \begin{aligned} 158)\quad &2\cdot10+5\cdot10^{-1}+10^2\\ &=20+0{,}5+100=120{,}5. \end{aligned} \]
Проверка, например, для №146: \(0{,}7\cdot10^{-2}=0{,}007\), \(5\cdot10^{-3}=0{,}005\), а \(0{,}007:0{,}005=1{,}4\).
