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Solve for x:
27^(2x)=(1/9)^(x-3)

User Evey
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2 Answers

3 votes

27^(2x)=\left((1)/(9)\right)^(x-3)\\ (3^3)^(2x)=(3^(-2))^(x-3)\\ 3^(6x)=3^(-2x+6)\\ 6x=-2x+6\\ 8x=6\\ x=(6)/(8)=(3)/(4)
User Holy Semicolon
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1 vote

27^(2x)=\left((1)/(9)\right)^(x-3)\\\\(3^3)^(2x)=\left((1)/(3^2)\right)^(x-3)\\\\3^(3\cdot2x)=(3^(-2))^(x-3)\\\\3^(6x)=3^(-2(x-3))\\\\3^(6x)=3^(-2x+6)\iff6x=-2x+6\ \ \ |add\ 2x\ to\ both\ sides\\\\8x=6\ \ \ |divide\ both\ sides\ by\ 8\\\\x=(6)/(8)\\\\\boxed{x=(3)/(4)}
User Giorgia Sambrotta
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7.9k points