What is the answer to 7^x=21 ?

The answer to 7^x=21 is x=(ln(21))/(ln(7))

The solution is x=(ln(21))/(ln(7))

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7^x=21

7^{x} = 21

x = \frac{ln ( 21 )}{ln ( 7 )}

Decimal Notation

x = 1.56457 \dots

Solution steps

7^{x} = 21

Apply exponent rules

x ln (7) = ln (21)

Solve

x ln (7) = ln (21) : x = \frac{ln ( 21 )}{ln ( 7 )}

x = \frac{ln ( 21 )}{ln ( 7 )}

\frac{1}{4} = 2^{x}

2^{b} = 16

4^{x} = 20

2^{2 x + 3} = 3^{3 x}

5^{x} - 75 \cdot 5^{- x} = 22