1)
[tex] \frac{nr \: caz \: favorabie}{nr \: caz \: posinbile} [/tex]
a)
[tex] \frac{1}{6} [/tex]
b)
[tex] \frac{4}{6} = \frac{2}{3} [/tex]
2)
a)
[tex] {3}^{2x - 1} = 81 \ \\ {3}^{2x - 1} = {3}^{4} \\ 2x - 1 = 4 \\ 2x = 4 + 1 \\ 2x = 5 \\ x = 5 \div 2 \\ x = \frac{5}{2} [/tex]
b) aici cred ca ai gresit ceva
[tex] {4}^{x} = 11 \\ [/tex]
c)
[tex] {25}^{x} - 4 \times {5}^{x} - 3 = 2 \\ {25}^{x} - {20}^{x} - 3 = {2} \\ {25}^{x} - {20}^{x} = 2 + 3 \\ {25}^{x} - {20}^{x} = 5 \\ {5}^{x } = {5}^{1} \\ x = 1[/tex]
