1 вариант:
а)
![5^1*5^{-5}=5^{1+(-5)}=5^{-4}=\frac{1}{5^4}=\frac{1}{625}](https://tex.z-dn.net/?f=5%5E1%2A5%5E%7B-5%7D%3D5%5E%7B1%2B%28-5%29%7D%3D5%5E%7B-4%7D%3D%5Cfrac%7B1%7D%7B5%5E4%7D%3D%5Cfrac%7B1%7D%7B625%7D)
б)
![3*(\frac{1}{3})^{-2}=3^1*3^{-1*-2}=3^1*3^2=3^{1+2}=3^3=27](https://tex.z-dn.net/?f=3%2A%28%5Cfrac%7B1%7D%7B3%7D%29%5E%7B-2%7D%3D3%5E1%2A3%5E%7B-1%2A-2%7D%3D3%5E1%2A3%5E2%3D3%5E%7B1%2B2%7D%3D3%5E3%3D27)
в)
![\frac{4^{-3}*2^6}{8}=\frac{2^{2*-3}*2^6}{2^3}=2^{-6+6-3}=2^{-3}=\frac{1}{2^3}=\frac{1}{8}](https://tex.z-dn.net/?f=%5Cfrac%7B4%5E%7B-3%7D%2A2%5E6%7D%7B8%7D%3D%5Cfrac%7B2%5E%7B2%2A-3%7D%2A2%5E6%7D%7B2%5E3%7D%3D2%5E%7B-6%2B6-3%7D%3D2%5E%7B-3%7D%3D%5Cfrac%7B1%7D%7B2%5E3%7D%3D%5Cfrac%7B1%7D%7B8%7D)
2 вариант.
а)
![2^1*2^{-3}=2^{1-3}=2^{-2}=\frac{1}{4}](https://tex.z-dn.net/?f=2%5E1%2A2%5E%7B-3%7D%3D2%5E%7B1-3%7D%3D2%5E%7B-2%7D%3D%5Cfrac%7B1%7D%7B4%7D)
б)
![(\frac{1}{4})^{-2}*4=4^{-1*-2}*4^1=4^{2+1}=4^3=64](https://tex.z-dn.net/?f=%28%5Cfrac%7B1%7D%7B4%7D%29%5E%7B-2%7D%2A4%3D4%5E%7B-1%2A-2%7D%2A4%5E1%3D4%5E%7B2%2B1%7D%3D4%5E3%3D64)
в)
![\frac{((3)^{-2})^3*27^2}{3}=\frac{3^{-2*3}*3^{3*2}}{3}=\frac{3^{-6+6}}{3}=\frac{1}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B%28%283%29%5E%7B-2%7D%29%5E3%2A27%5E2%7D%7B3%7D%3D%5Cfrac%7B3%5E%7B-2%2A3%7D%2A3%5E%7B3%2A2%7D%7D%7B3%7D%3D%5Cfrac%7B3%5E%7B-6%2B6%7D%7D%7B3%7D%3D%5Cfrac%7B1%7D%7B3%7D)
Качество фото не лучшее, поэтому мог записать некоторые примеры неправильно.
-sin x = - cos 2x
-sin x +1-2sin^2(x)=0
2a^2 +a -1 = 0
a = 1/2 a = -1
sin x = 1/2 , x = (-1)^n pi/6 +pin
sin x = -1 x = -pi/2 +2pin
Объяснение:
![\left \{ {{y=mx} \atop {y=7x-2}} \right. \left \{ {{mx-y=0} \atop {7x-y=2}} \right. \; \; \to \; \; \; \frac{m}{7}=\frac{-1}{-1}\ne \frac{0}{2}\\\\\frac{m}{7}=1\ne 0](https://tex.z-dn.net/?f=%5Cleft+%5C%7B+%7B%7By%3Dmx%7D+%5Catop+%7By%3D7x-2%7D%7D+%5Cright.+%5Cleft+%5C%7B+%7B%7Bmx-y%3D0%7D+%5Catop+%7B7x-y%3D2%7D%7D+%5Cright.+%5C%3B+%5C%3B+%5Cto+%5C%3B+%5C%3B+%5C%3B+%5Cfrac%7Bm%7D%7B7%7D%3D%5Cfrac%7B-1%7D%7B-1%7D%5Cne+%5Cfrac%7B0%7D%7B2%7D%5C%5C%5C%5C%5Cfrac%7Bm%7D%7B7%7D%3D1%5Cne+0)
a) Система не имеет решений, если m=7 . Тогда прямые, заданные 1-ым и 2-ым уравнениями системы, будут параллельны ( не пересекаются).
б) Система будет иметь единственное решение, если m≠7 .
Решение в фотке:
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