Final answer:
To find x in the equation D log 10(x+7) - log 10(x-7)= 1, use logarithmic properties to simplify the equation, convert it to exponential form, and solve for x, giving x = 9.
Step-by-step explanation:
To find x in the equation D log10(x+7) - log10(x-7) = 1, we will use logarithmic properties.
First, combine the logarithms using the property logb(a) - logb(c) = logb(a/c). So we have D log10((x+7)/(x-7)) = 1.
Next, convert the logarithmic equation into exponential form, giving 101 = (x+7)/(x-7).
Simplifying further, we have 10 = (x+7)/(x-7).
Cross-multiply and solve for x. Thus, x = 9.
Learn more about Logarithmic properties