Simplify 1/(3x^3)+1/5

$\frac{1}{3 x^{3}} + \frac{1}{5}$

To write $\frac{1}{3 x^{3}}$ as a fraction with a common denominator, multiply by $\frac{5}{5}$ .

$\frac{1}{3 x^{3}} \cdot \frac{5}{5} + \frac{1}{5}$

To write $\frac{1}{5}$ as a fraction with a common denominator, multiply by $\frac{3 x^{3}}{3 x^{3}}$ .

$\frac{1}{3 x^{3}} \cdot \frac{5}{5} + \frac{1}{5} \cdot \frac{3 x^{3}}{3 x^{3}}$

Write each expression with a common denominator of $15 x^{3}$ , by multiplying each by an appropriate factor of $1$ .

Multiply $\frac{1}{3 x^{3}}$ by $\frac{5}{5}$ .

$\frac{5}{3 x^{3} \cdot 5} + \frac{1}{5} \cdot \frac{3 x^{3}}{3 x^{3}}$

Multiply $5$ by $3$ .

$\frac{5}{15 x^{3}} + \frac{1}{5} \cdot \frac{3 x^{3}}{3 x^{3}}$

Multiply $\frac{1}{5}$ by $\frac{3 x^{3}}{3 x^{3}}$ .

$\frac{5}{15 x^{3}} + \frac{3 x^{3}}{5 (3 x^{3})}$

Multiply $3$ by $5$ .

$\frac{5}{15 x^{3}} + \frac{3 x^{3}}{15 x^{3}}$

Combine the numerators over the common denominator.

$\frac{5 + 3 x^{3}}{15 x^{3}}$