SOLUTION: If 4^x=7, what does 4^-2x equal? Please help

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Question 163263This question is from textbook Precalculus
: If 4^x=7, what does 4^-2x equal? Please help This question is from textbook Precalculus

Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
If 4%5Ex+=+7, find 4%5E%28-2x%29
4%5E%28-2x%29+=+1%2F%284%5E%282x%29%29=1%2F%284%5Ex%2A4%5Ex%29+=+1%2F%287%2A7%29=highlight%281%2F49%29