Question

Решите уравнения 1)4^(-x)-7*2^(-x)=-4 2)128*16^(2x+1)=8^(3-2x)

Answer 1

$128 \times {16}^{(2x + 1)} = {8}^{(3 - 2x)} \\ {2}^{7} \times {2}^{(8x + 4)} = {2}^{(9 - 6x)} \\ {2}^{(8x + 11)} = {2}^{(9 - 6x)} \\ 8x + 11 = 9 - 6x \\ 8x + 6x = 9 - 11 \\ 14x = - 2 \\ x = - \frac{2}{14} \\ x= - \frac{1}{7}$