Basic Operations

Basic Operations

Subtracting Functions

To subtract functions, first change the sign of every term being subtracted using the Distributive Property. Eliminate the parentheses and combine like terms.

Example Given f(x) = 3x2 +4x – 5 and g(x) = 2x2 - 6x + 5, find f(x) - g(x).

Step 1. Replace f(x) and g(x) with their equivalent expressions.

f(x) - g(x)

(3x2 + 4x – 5) - (2x2 - 6x + 5)

Step 2. Use the Distributive Property to change the sign of every term in g(x).

(3x2 +4x – 5) + (- 2x2 + 6x – 5)

Step 3. Eliminate the parentheses and combine like terms.

3x2 +4x – 5 - 2x2 + 6x – 5

(3x2– 2x2) + (4x + 6x) + (-5 – 5)

x 2 + 10x – 10