![b_{n}=b_{1}q^{n-1}](https://tex.z-dn.net/?f=b_%7Bn%7D%3Db_%7B1%7Dq%5E%7Bn-1%7D)
Найдем ![b_{2}](https://tex.z-dn.net/?f=b_%7B2%7D)
подставляем в формулу n=2
![b_{2}=12*2^{2-1}=12*2=24](https://tex.z-dn.net/?f=b_%7B2%7D%3D12%2A2%5E%7B2-1%7D%3D12%2A2%3D24)
Найдем ![b_{3}](https://tex.z-dn.net/?f=b_%7B3%7D)
подставляем в формулу n=3
![b_{3}=12*2^{3-1}=12*2^{2}=12*4=48](https://tex.z-dn.net/?f=b_%7B3%7D%3D12%2A2%5E%7B3-1%7D%3D12%2A2%5E%7B2%7D%3D12%2A4%3D48)
Найдем ![b_{4}](https://tex.z-dn.net/?f=b_%7B4%7D)
подставляем в формулу n=4
![b_{4}=12*2^{4-1}=12*2^{3}=12*8=96](https://tex.z-dn.net/?f=b_%7B4%7D%3D12%2A2%5E%7B4-1%7D%3D12%2A2%5E%7B3%7D%3D12%2A8%3D96)
Найдем ![b_{5}](https://tex.z-dn.net/?f=b_%7B5%7D)
подставляем в формулу n=5
![b_{5}=12*2^{5-1}=12*2^{4}=12*16=192](https://tex.z-dn.net/?f=b_%7B5%7D%3D12%2A2%5E%7B5-1%7D%3D12%2A2%5E%7B4%7D%3D12%2A16%3D192)
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Ответ:
а)4
в)a+y-9
д)-2+5x
б)-8
г)-3m+x+3m=x
e)3x+7x
2.
a)3,8-9,4+5,6=-11,2
б)-8×(18,3+1,25)=-146,4-10=-156,4
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