Solve 7(-3a)+6(-a)=

$$7 ( - 3 a ) + 6 ( - a ) =$$

Evaluate

$$-27a$$

Solution Steps

Multiply 7 and -3 to get -21.

$$-21a+6\left(-a\right)$$

Multiply 6 and -1 to get -6.

$$-21a-6a$$

Combine -21a and -6a to get -27a.

$$-27a$$

Differentiate w.r.t. a

$$-27$$

Steps Using Definition of a Derivative

Multiply 7 and -3 to get -21.

$$\frac{\mathrm{d}}{\mathrm{d}a}(-21a+6\left(-a\right))$$

Multiply 6 and -1 to get -6.

$$\frac{\mathrm{d}}{\mathrm{d}a}(-21a-6a)$$

Combine -21a and -6a to get -27a.

$$\frac{\mathrm{d}}{\mathrm{d}a}(-27a)$$

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

$$-27a^{1-1}$$

Subtract 1 from 1.

$$-27a^{0}$$

For any term t except 0, t^{0}=1.

$$-27$$