Solve r:x^2-25

$$r : x ^ { 2 } - 25$$

Evaluate

$$-25+\frac{r}{x^{2}}$$

Short Solution Steps

To add or subtract expressions, expand them to make their denominators the same. Multiply 25 times \frac{x^{2}}{x^{2}}.

$$\frac{r}{x^{2}}-\frac{25x^{2}}{x^{2}}$$

Since \frac{r}{x^{2}} and \frac{25x^{2}}{x^{2}} have the same denominator, subtract them by subtracting their numerators.

$$\frac{r-25x^{2}}{x^{2}}$$

Differentiate w.r.t. x

$$-\frac{2r}{x^{3}}$$