81b2-1=0

Add 1 to both sides of the equation.

81b2=1

Divide each term in 81b2=1 by 81.

81b281=181

Cancel the common factor of 81.

Cancel the common factor.

81b281=181

Divide b2 by 1.

b2=181

b2=181

b2=181

Take the square root of both sides of the equation to eliminate the exponent on the left side.

b=±181

Simplify the right side of the equation.

Rewrite 181 as 181.

b=±181

Any root of 1 is 1.

b=±181

Simplify the denominator.

Rewrite 81 as 92.

b=±192

Pull terms out from under the radical, assuming positive real numbers.

b=±19

b=±19

b=±19

The complete solution is the result of both the positive and negative portions of the solution.

First, use the positive value of the ± to find the first solution.

b=19

Next, use the negative value of the ± to find the second solution.

b=-19

The complete solution is the result of both the positive and negative portions of the solution.

b=19,-19

b=19,-19

b=19,-19

The result can be shown in multiple forms.

Exact Form:

b=19,-19

Decimal Form:

b=0.1‾,-0.1‾

Solve for b 81b^2-1=0