(1/5)^(3–2x)=125
5^(–(3–2x)) = 5^3
основания степеней равны, значит, и показатели равны
–(3–2х) = 3
– 3 + 2х = 3
2х = 6
х=6:2
х=3 Ответ: х = 3
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3^(2x+1) – 28*3^x + 9 = 0
3^2x * 3 – 28*3^x + 9 = 0
3^x=y
3y^2 – 28y + 9 = 0
D = 28^2 – 4*3*9 = 784-108=676
√D = 26
y1 = (28+26)/6 = 9
3^x=9
3^x=3^2
x=2
y2 = (28–26)/6= 1/3
3^x = 1/3
3^x = 3^(–1)
x= –1
ответ: х1 = 2 и х2 = – 1
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2^(x+5) – 2^x = 62
2^x * 2^5 – 2^x = 62
2^x * (32 – 1) = 62
2^x = 62:31
2^x = 2^1
x=1
Ответ: х=1