Question

Help :)

Solve the equation.

Log(x+7)- Logx=3

A. 3.5
B. 142.7
C. 0.0070
D. 0.0707

Answer 1

@bibby

Answer 2

properties of logs:\(\log_b(\dfrac{m}{n}) = \log_b(m) – \log_b(n)\)

Answer 3

So would i do logb (7/3)= logb (7)- logb (3)?

Answer 4

here, b is 10
\(\log(x+7)- \log x=3\\\log(\dfrac{x+7}{x})=3\\10^3=\dfrac{x+7}{x}\\1000x=x+7\\999x=7\\x=\dfrac{7}{999}
\)