Log3 (x+1)+log3 (x+3)=1

[latex] log_{3}(x+1) + log_{3}(x+3) = 1 \\ log_{3}((x+1)(x+3))=1\\ (x+1)(x+3)=3^1\\ x^2+4x=0 \\ x=0 ; x=-4 \\ [/latex]  Ответ [latex] x=0[/latex]