Solve -9f^2+2f^2+-8f^2

$$- 9 f ^ { 2 } + 2 f ^ { 2 } + - 8 f ^ { 2 }$$

Evaluate

$$-15f^{2}$$

Solution Steps

Combine -9f^{2} and 2f^{2} to get -7f^{2}.

$$-7f^{2}-8f^{2}$$

Combine -7f^{2} and -8f^{2} to get -15f^{2}.

$$-15f^{2}$$

Differentiate w.r.t. f

$$-30f$$

Steps Using Definition of a Derivative

Combine -9f^{2} and 2f^{2} to get -7f^{2}.

$$\frac{\mathrm{d}}{\mathrm{d}f}(-7f^{2}-8f^{2})$$

Combine -7f^{2} and -8f^{2} to get -15f^{2}.

$$\frac{\mathrm{d}}{\mathrm{d}f}(-15f^{2})$$

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

$$2\left(-15\right)f^{2-1}$$

Multiply 2 times -15.

$$-30f^{2-1}$$

Subtract 1 from 2.

$$-30f^{1}$$

For any term t, t^{1}=t.

$$-30f$$