Question

даю 20 балов!!! 4*3^(x+2)+5*3^(x)-7*3^(x+1)=60

Answer 1

Ответ:

$4 \times {3}^{x + 2} + 5 \times {3}^{x} - 7 \times {3}^{x + 1} = 60 \\ {3}^{x} (4 \times 9 + 5 - 7 \times 3) = 60 \\ {3}^{x} \times 20 = 60 \\ {3}^{x} = 3 \\ x = 1$