Math Problem Statement

Suppose that the functions g and h are defined for all real numbers x as follows: g(x) = 4x - 5, h(x) = x + 6. Write the expressions for (g + h)(x) and (g ⋅ h)(x) and evaluate (g − h)(3).

Solution

Let's solve the given problem step by step.

We are given the following functions:

g(x)=4x5g(x) = 4x - 5 h(x)=x+6h(x) = x + 6

We need to:

  1. Find (g+h)(x)(g + h)(x)
  2. Find (gh)(x)(g \cdot h)(x)
  3. Evaluate (gh)(3)(g - h)(3)

1. (g+h)(x)(g + h)(x):

This is the sum of g(x)g(x) and h(x)h(x):

(g+h)(x)=g(x)+h(x)=(4x5)+(x+6)(g + h)(x) = g(x) + h(x) = (4x - 5) + (x + 6) Simplifying: (g+h)(x)=4x5+x+6=5x+1(g + h)(x) = 4x - 5 + x + 6 = 5x + 1

2. (gh)(x)(g \cdot h)(x):

This is the product of g(x)g(x) and h(x)h(x):

(gh)(x)=g(x)h(x)=(4x5)(x+6)(g \cdot h)(x) = g(x) \cdot h(x) = (4x - 5)(x + 6) Using the distributive property (FOIL): (gh)(x)=4x(x+6)5(x+6)=4x2+24x5x30(g \cdot h)(x) = 4x(x + 6) - 5(x + 6) = 4x^2 + 24x - 5x - 30 Simplifying: (gh)(x)=4x2+19x30(g \cdot h)(x) = 4x^2 + 19x - 30

3. (gh)(3)(g - h)(3):

This is the difference between g(3)g(3) and h(3)h(3). Let's first find g(3)g(3) and h(3)h(3):

g(3)=4(3)5=125=7g(3) = 4(3) - 5 = 12 - 5 = 7 h(3)=3+6=9h(3) = 3 + 6 = 9

Now, subtract: (gh)(3)=g(3)h(3)=79=2(g - h)(3) = g(3) - h(3) = 7 - 9 = -2

Final Answers:

  1. (g+h)(x)=5x+1(g + h)(x) = 5x + 1
  2. (gh)(x)=4x2+19x30(g \cdot h)(x) = 4x^2 + 19x - 30
  3. (gh)(3)=2(g - h)(3) = -2

Would you like further details or have any other questions?

Here are 5 related questions to explore further:

  1. What is (g/h)(x)(g/h)(x) for these functions?
  2. How would you find (g2+h2)(x)(g^2 + h^2)(x)?
  3. Can you find the domain of the function g/h(x)g/h(x)?
  4. What is the derivative of (gh)(x)(g \cdot h)(x)?
  5. How would you graph the functions g(x)g(x) and h(x)h(x) together?

Tip: Always simplify expressions before evaluating specific values to avoid errors during calculations.

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Math Problem Analysis

Mathematical Concepts

Algebra
Functions
Polynomials

Formulas

(g + h)(x) = g(x) + h(x)
(g ⋅ h)(x) = g(x) ⋅ h(x)
(g − h)(3) = g(3) − h(3)

Theorems

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Suitable Grade Level

Grades 9-12