Question

  3^2x=81

3 (x-4)+3=x+1

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Answer 1

3^2x=81=3⁴

\(\Rightarrow\)2x=4

\(\Rightarrow\)x=4:2

\(\Rightarrow\)x=2

Answer 2

\(3^{2x}=81\)

\(3^{2x}=3^4\)

\(\Rightarrow2x=4\)

\(\Rightarrow x=2\)

vậy \(x=2\)

\(3\left(x-4\right)+3=x+1\)

\(3x-12+3=x+1\)

\(3x-x=1+12-3\)

\(2x=10\)

\(x=5\)

vậy \(x=5\)

học vui Quế Vũ