Solve 1/3^2-1/9^2=

$$\frac { 1 } { 3 ^ { 2 } } - \frac { 1 } { 9 ^ { 2 } } =$$

Evaluate

$$\frac{8}{81}\approx 0.098765432$$

Solution Steps

Calculate 3 to the power of 2 and get 9.

$$\frac{1}{9}-\frac{1}{9^{2}}$$

Calculate 9 to the power of 2 and get 81.

$$\frac{1}{9}-\frac{1}{81}$$

Least common multiple of 9 and 81 is 81. Convert \frac{1}{9} and \frac{1}{81} to fractions with denominator 81.

$$\frac{9}{81}-\frac{1}{81}$$

Since \frac{9}{81} and \frac{1}{81} have the same denominator, subtract them by subtracting their numerators.

$$\frac{9-1}{81}$$

Subtract 1 from 9 to get 8.

$$\frac{8}{81}$$

Factor

$$\frac{2 ^ {3}}{3 ^ {4}} = 0.09876543209876543$$