Solve the equation LaTeX:  \displaystyle \log_{10}(x + 10001)-\log_{10}(x + 1001)=1 .

Using the quotient property of logarithms gives LaTeX:  \displaystyle \log_{10}\frac{x + 10001}{x + 1001} = 1 . Making both sides of the equation exponents on the base LaTeX:  \displaystyle 10 gives LaTeX:  \displaystyle \frac{x + 10001}{x + 1001}=10 . Clearing the fractions by multiplying by the LCD gives LaTeX:  \displaystyle x + 10001=10 x + 10010 . Isolating LaTeX:  \displaystyle x gives LaTeX:  \displaystyle x = -1 .