Logaritmujeme (expon. rovnice)
a) 3^ = 10
b) 5^x-1 = 4
c) 2^x * 3^x-1= 6
d) 5^x * 7^2x = 16^x-1
e) 16^x = 8 * 4^x + 2 * 8^x
b) 5^x-1 = 4
c) 2^x * 3^x-1= 6
d) 5^x * 7^2x = 16^x-1
e) 16^x = 8 * 4^x + 2 * 8^x
Odpovědi
Diskuze
x=log3 (10)
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b) 5^x-1 = 4
5^(x-1) = 4
(x-1) = log5(4)
x = 1+log5(4)
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c) 2^x * 3^x-1= 6
2^x * 3^(x-1) = 6
2^x * 3^x/3 = 6
(2*3)^x = 6*3
6^x = 6*3
x = log6(6*3)
x = log6(6)+log6(3)
x = 1+log6(3)
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nebo
x = log6(6*6/2)
x = log6(6)+log6(6) - log6(2)
x = 2-log6(2)
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