389
Используем \(\sqrt{t^2}=|t|\):
\[ \begin{aligned} \text{а)}&\ \sqrt{a^2}=a;\\ \text{б)}&\ \sqrt{n^2}=-n;\\ \text{в)}&\ 3\sqrt{c^2}=3c;\\ \text{г)}&\ -5\sqrt{y^2}=-5y;\\ \text{д)}&\ \sqrt{36x^2}=6|x|=-6x;\\ \text{е)}&\ -\sqrt{9y^2}=-3|y|=3y;\\ \text{ж)}&\ -5\sqrt{4x^2}=-10|x|=-10x;\\ \text{з)}&\ 0{,}5\sqrt{16a^2}=2|a|=-2a. \end{aligned} \]
Обсуждение
2 сообщения394 и 395
394. \[ \begin{aligned} \text{а)}&\ \sqrt{2^4}=2^2=4;\\ \text{б)}&\ \sqrt{3^4}=3^2=9;\\ \text{в)}&\ \sqrt{2^6}=2^3=8;\\ \text{г)}&\ \sqrt{10^8}=10^4=10000;\\ \text{д)}&\ \sqrt{(-5)^4}=(-5)^2=25;\\ \text{е)}&\ \sqrt{(-2)^8}=(-2)^4=16;\\ \text{ж)}&\ \sqrt{3^4\cdot5^2}=3^2\cdot5=45;\\ \text{з)}&\ \sqrt{2^6\cdot7^4}=2^3\cdot7^2=8\cdot49=392. \end{aligned} \]
395. \[ \begin{aligned} \text{а)}&\ \sqrt{11^4}=11^2=121;\\ \text{б)}&\ \sqrt{4^6}=4^3=64;\\ \text{в)}&\ \sqrt{(-3)^6}=3^3=27;\\ \text{г)}&\ \sqrt{(-6)^4}=6^2=36;\\ \text{д)}&\ \sqrt{2^8\cdot3^2}=2^4\cdot3=48;\\ \text{е)}&\ \sqrt{3^4\cdot5^6}=3^2\cdot5^3=9\cdot125=1125;\\ \text{ж)}&\ \sqrt{7^2\cdot2^8}=7\cdot2^4=112;\\ \text{з)}&\ \sqrt{3^6\cdot5^4}=3^3\cdot5^2=27\cdot25=675;\\ \text{и)}&\ \sqrt{8^4\cdot5^6}=8^2\cdot5^3=64\cdot125=8000. \end{aligned} \]
