Решите уравнение логорифмическое

Х+1≠0
х≠ -1
$\frac{x+4}{15} \ \textgreater \ 0 \\ x+4\ \textgreater \ 0 \\ x\ \textgreater \ -4 \\ \frac{5}{x+1} \ \textgreater \ 0 \\ x+1\ \textgreater \ 0 \\ x\ \textgreater \ -1 \\ \\$
x∈(-1; +∞)
$log _{7} ( \frac{x+4}{15} * \frac{5}{x+1}) = 1 \\ log_{7} ( \frac{x+4}{3(x+1)}) =1 \\ \frac{x+4}{3(x+1)} = 7^{1} \\ \frac{x+4}{3(x+1)} =7 \\ x+4 =3*7(x+1) \\ x+4 = 21(x+1) \\ x+4 =21x +21 \\ x-21x = 21-4 \\ -20x = 17 \\ x = - \frac{17}{20}$
x = -0.85