Take the natural logarithm of both sides of the equation to remove the variable from the exponent.

Expand by moving outside the logarithm.

Apply the distributive property.

Multiply by .

Move all the terms containing a logarithm to the left side of the equation.

Use the quotient property of logarithms, .

Subtract from both sides of the equation.

Divide each term in by .

Cancel the common factor of .

Cancel the common factor.

Divide by .

Move the negative in front of the fraction.

The result can be shown in multiple forms.

Exact Form:

Decimal Form:

Solve for x 4^(x+1)=21