Question

Solve for x algebraically in 7^(-x+2) = 0.005, rounding your answers to three signicant digits.

A) 4.32
B) 4.72
C) 5.12
D) 5.52
E) 5.92

Answer 1

You'll need to use logs for this.

Answer 2

Do I use 7ln(-x+2) = ln 0.005 ???

Answer 3

You do take the log of both sides, but I would suggest using log base 10 and what you have there isn't quite correct even if you were going to use the natural log.

Answer 4

Remember that
\[log(a^b) = b*log(a)\]