lg X + lg (x+2) = lg 3
0\\lgx(x+2)=lg3\\x^2+2x=3\\x^2+2x-3=0\\(x+3)(x-1)=0\\x=1" alt="lg X + lg (x+2) = lg 3\\OD3:x>0\\lgx(x+2)=lg3\\x^2+2x=3\\x^2+2x-3=0\\(x+3)(x-1)=0\\x=1" align="absmiddle" class="latex-formula">