Solve 90*90/100x

$$\frac { 90 \times 90 } { 100 x }$$

Evaluate

$$\frac{81}{x}$$

Solution Steps

Cancel out 10\times 10 in both numerator and denominator.

$$\frac{9\times 9}{x}$$

Multiply 9 and 9 to get 81.

$$\frac{81}{x}$$

Differentiate w.r.t. x

$$-\frac{81}{x^{2}}$$

Steps Using Definition of a Derivative

Cancel out 10\times 10 in both numerator and denominator.

$$\frac{\mathrm{d}}{\mathrm{d}x}(\frac{9\times 9}{x})$$

Multiply 9 and 9 to get 81.

$$\frac{\mathrm{d}}{\mathrm{d}x}(\frac{81}{x})$$

The derivative of ax^{n} is nax^{n-1}.

$$-81x^{-1-1}$$

Subtract 1 from -1.

$$-81x^{-2}$$