Question

If f(x) = 4x - 3 and g(x) = x + 4, find (f - g)(x)

Answer 1

3x - 7

Explanation:

This questions asks about the subtraction of functions. To find the answer, we can subtract the same way we would subtract polynomials.

Subtracting Expressions

First, set up the subtraction problem by taking the expression for f(x) and subtracting the expression equal to g(x) from it.

This looks like:

• (4x - 3) - (x + 4)

Next, distribute the negative to the second binomial

• 4x - 3 - x - 4

Then, combine like terms

• 3x - 7

Since we are not given a x-value, this is the final answer.

Solving for an X-Value

If you are given an x-value, the best way to solve the equation is to first solve each function and then subtract.

For example, using the same rules for each function let's solve (f-g)(2).

First, solve for f(2) and g(2)

• f(2) = 5
• g(2) = 6

Then, subtract the 2 values

• 5 - 6 = -1