c)
[tex] {5}^{x + 2} \times {2}^{x + 1} + 7 \times {10}^{x} = 57000 \\ 5x \times {5}^{2} \times {2}^{x} \times 2 + 7 \times {10}^{x} = 57000 \\ {5}^{x} \times 25 \times {2}^{x} \times 2 + 7 \times {10}^{x} = 57000 \\ {(5 \times 2)}^{x} \times 25 \times 2 + 7 \times {10}^{x} = 57000 \\ {10}^{x} \times 25 \times 2 + 7 \times {10}^{x} = 57000 {10}^{x} \times 50 + 7 \times {10}^{x} = 57000 \\ 50 \times {10}^{x} + 7 \times {10}^{x} = 57000 \\ 57 \times {10}^{x} = 57000 \\ {10}^{x} = 1000 \\ {10}^{x} = {10}^{3 } \\ x = 3[/tex]
d)
[tex]12 \times {4}^{x} - 5 \times {4}^{x} = 7 \times {2}^{12} \\ 7 \times {4}^{x} = 7 \times 4096 \\ 7 \times {4}^{ \times } = 28672 \\ {4}^{x} = 4096 \\ {4}^{x} = {4}^{6} \\ x = 6[/tex]
e)
[tex] {4}^{x + 2} + {4}^{x + 1} + {4}^{x} = 336 \\ ( {4}^{2} + 4 + 1) \times {4}^{x} 336 \\ (16 + 4 + 1) \times {4}^{x} = 336 \\ 21 \times {4}^{x} = 336 \\ {4}^{x} = 16 \\ {4}^{x} = {4}^{2} \\ x = 2[/tex]
doar atît am făcut,pentru că e foarte mult
