Adding & Subtracting

Subtracting

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) = 2x2 and g(x) = 3x2+ 1, what is f(x) - g(x)?

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

f(x) - g(x)

(2x2) - (3x2 + 1)

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

2x2 - 3x2 - 1

Step 3. Combine like terms.

-1x2 - 1 or -x2 - 1