Question

Решите пожалуйста 2 вариант срочно

Answer 1

Ответ:

$1){3}^{x + 3} + {3}^{x} = 84 \\ ( {3}^{3} + 1) \times {3}^{x} = 84 \\ (27 + 1) \times {3}^{x} = 84 \\ 28 \times {3}^{x} = 84 \\ {3}^{x} = 3 \\ {3}^{x} = {3}^{1} \\ x = 1$

$2)5 \times {4}^{x + 1} + {4}^{x} = 84 \\ (5 \times 4 + 1) \times {4}^{x} = 84 \\ 21 \times {4}^{x} = 84 \\ {4}^{x} = 4 \\ {4}^{x} = {4}^{1} \\ x = 1$

$3)3 \times {8}^{x} + {8}^{x - 2} = 193 \\ (3 \times {8}^{2} + 1) \times {8}^{x - 2} = 193 \\ 193 \times {8}^{x - 2} = 193 \\ {8}^{x - 2} = 1 \\ {8}^{x - 2} = {8}^{0} \\ x - 2 = 0 \\ x = 2$

$4)3 \times {5}^{x + 1} - 6 \times {5}^{x - 1} - {5}^{x} = 320 \\ (3 \times {5}^{2} - 6 - 5) \times {5}^{ x - 1 } = 320 \\ 64 \times {5}^{x - 1} = 320 \\ {5}^{x - 1} = 5 \\ {5}^{x - 1} = {5}^{1} \\ x - 1 = 1 \\ x = 2$

$5) {6}^{2x - 1} + {6}^{2x - 2} - {6}^{2x - 3} = 246 \\ ( {6}^{2} + 6 - 1) \times {6}^{2x - 3} = 246 \\ 41 \times {6}^{2x - 3} = 246 \\ {6}^{2x - 3} = 6 \\ {6}^{2x - 3} = {6}^{1} \\ 2x - 3 = 1 \\ 2x = 4 \\ x = 2$