Solve a+2a-7a+9a

$$a + 2 a - 7 a + 9 a$$

Evaluate

$$5a$$

Solution Steps

Combine a and 2a to get 3a.

$$3a-7a+9a$$

Combine 3a and -7a to get -4a.

$$-4a+9a$$

Combine -4a and 9a to get 5a.

$$5a$$

Differentiate w.r.t. a

$$5$$

Steps Using Definition of a Derivative

Combine a and 2a to get 3a.

$$\frac{\mathrm{d}}{\mathrm{d}a}(3a-7a+9a)$$

Combine 3a and -7a to get -4a.

$$\frac{\mathrm{d}}{\mathrm{d}a}(-4a+9a)$$

Combine -4a and 9a to get 5a.

$$\frac{\mathrm{d}}{\mathrm{d}a}(5a)$$

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

$$5a^{1-1}$$

Subtract 1 from 1.

$$5a^{0}$$

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

$$5\times 1$$

For any term t, t\times 1=t and 1t=t.

$$5$$