Simplify (5y^3)/(x^2)+4x

$\frac{5 y^{3}}{x^{2}} + 4 x$

To write $4 x$ as a fraction with a common denominator, multiply by $\frac{x^{2}}{x^{2}}$ .

$\frac{5 y^{3}}{x^{2}} + \frac{4 x \cdot x^{2}}{x^{2}}$

Combine the numerators over the common denominator.

$\frac{5 y^{3} + 4 x \cdot x^{2}}{x^{2}}$

Multiply $x$ by $x^{2}$ by adding the exponents.

Move $x^{2}$ .

$\frac{5 y^{3} + 4 (x^{2} x)}{x^{2}}$

Multiply $x^{2}$ by $x$ .

Raise $x$ to the power of $1$ .

$\frac{5 y^{3} + 4 (x^{2} x^{1})}{x^{2}}$

Use the power rule $a^{m} a^{n} = a^{m + n}$ to combine exponents.

$\frac{5 y^{3} + 4 x^{2 + 1}}{x^{2}}$

Add $2$ and $1$ .

$\frac{5 y^{3} + 4 x^{3}}{x^{2}}$