Math Problem Statement

Given the functions: f(x)=8x g(x)=x+7 h(x)=3x^2 +23x+14 Determine each of the following.

Give your answers as simplified expressions written in descending order.

Find and simplify g(x)+h(x)

Find and simplify h(x)-g(x)

Find and simplify f(x)times h(x)
Find and simplify h(x) / g(x) , hint: you will need to factor h(x)

The domain restriction for g(x) / f(x)

is x cannot equal

Solution

Let's solve each of the given expressions step by step.

1. Find and simplify g(x)+h(x)g(x) + h(x)

We are given:

  • g(x)=x+7g(x) = x + 7
  • h(x)=3x2+23x+14h(x) = 3x^2 + 23x + 14

To find g(x)+h(x)g(x) + h(x), simply add these two functions:

g(x)+h(x)=(x+7)+(3x2+23x+14)g(x) + h(x) = (x + 7) + (3x^2 + 23x + 14)

Combine like terms:

g(x)+h(x)=3x2+(23x+x)+(14+7)g(x) + h(x) = 3x^2 + (23x + x) + (14 + 7) g(x)+h(x)=3x2+24x+21g(x) + h(x) = 3x^2 + 24x + 21

So, the simplified expression is:

g(x)+h(x)=3x2+24x+21g(x) + h(x) = 3x^2 + 24x + 21


2. Find and simplify h(x)g(x)h(x) - g(x)

We are given:

  • g(x)=x+7g(x) = x + 7
  • h(x)=3x2+23x+14h(x) = 3x^2 + 23x + 14

To find h(x)g(x)h(x) - g(x), subtract the two functions:

h(x)g(x)=(3x2+23x+14)(x+7)h(x) - g(x) = (3x^2 + 23x + 14) - (x + 7)

Distribute the negative sign and combine like terms:

h(x)g(x)=3x2+23x+14x7h(x) - g(x) = 3x^2 + 23x + 14 - x - 7 h(x)g(x)=3x2+(23xx)+(147)h(x) - g(x) = 3x^2 + (23x - x) + (14 - 7) h(x)g(x)=3x2+22x+7h(x) - g(x) = 3x^2 + 22x + 7

So, the simplified expression is:

h(x)g(x)=3x2+22x+7h(x) - g(x) = 3x^2 + 22x + 7


3. Find and simplify f(x)×h(x)f(x) \times h(x)

We are given:

  • f(x)=8xf(x) = 8x
  • h(x)=3x2+23x+14h(x) = 3x^2 + 23x + 14

To find f(x)×h(x)f(x) \times h(x), multiply these two functions:

f(x)×h(x)=8x(3x2+23x+14)f(x) \times h(x) = 8x(3x^2 + 23x + 14)

Distribute 8x8x to each term in h(x)h(x):

f(x)×h(x)=8x×3x2+8x×23x+8x×14f(x) \times h(x) = 8x \times 3x^2 + 8x \times 23x + 8x \times 14 f(x)×h(x)=24x3+184x2+112xf(x) \times h(x) = 24x^3 + 184x^2 + 112x

So, the simplified expression is:

f(x)×h(x)=24x3+184x2+112xf(x) \times h(x) = 24x^3 + 184x^2 + 112x


4. Find and simplify h(x)g(x)\frac{h(x)}{g(x)}

We are given:

  • g(x)=x+7g(x) = x + 7
  • h(x)=3x2+23x+14h(x) = 3x^2 + 23x + 14

To find h(x)g(x)\frac{h(x)}{g(x)}, we need to factor h(x)h(x) and check if any common factors can be canceled.

First, factor h(x)=3x2+23x+14h(x) = 3x^2 + 23x + 14:

Find two numbers that multiply to 3×14=423 \times 14 = 42 and add to 23. These numbers are 21 and 2.

So, we can factor h(x)h(x) as follows:

h(x)=3x2+21x+2x+14h(x) = 3x^2 + 21x + 2x + 14 h(x)=3x(x+7)+2(x+7)h(x) = 3x(x + 7) + 2(x + 7) h(x)=(3x+2)(x+7)h(x) = (3x + 2)(x + 7)

Now, simplify h(x)g(x)\frac{h(x)}{g(x)}:

h(x)g(x)=(3x+2)(x+7)x+7\frac{h(x)}{g(x)} = \frac{(3x + 2)(x + 7)}{x + 7}

Cancel the common factor (x+7)(x + 7):

h(x)g(x)=3x+2\frac{h(x)}{g(x)} = 3x + 2

So, the simplified expression is:

h(x)g(x)=3x+2\frac{h(x)}{g(x)} = 3x + 2


5. Domain restriction for g(x)f(x)\frac{g(x)}{f(x)}

We are given:

  • g(x)=x+7g(x) = x + 7
  • f(x)=8xf(x) = 8x

To find the domain restriction for g(x)f(x)\frac{g(x)}{f(x)}, remember that division by zero is undefined. Set f(x)=0f(x) = 0 and solve for xx:

8x=08x = 0 x=0x = 0

So, the domain restriction is x0x \neq 0.


Summary:

  1. g(x)+h(x)=3x2+24x+21g(x) + h(x) = 3x^2 + 24x + 21
  2. h(x)g(x)=3x2+22x+7h(x) - g(x) = 3x^2 + 22x + 7
  3. f(x)×h(x)=24x3+184x2+112xf(x) \times h(x) = 24x^3 + 184x^2 + 112x
  4. h(x)g(x)=3x+2\frac{h(x)}{g(x)} = 3x + 2
  5. Domain restriction for g(x)f(x)\frac{g(x)}{f(x)}: x0x \neq 0

Would you like further explanation on any of the steps?

Related Questions:

  1. How would the results change if f(x)=8x2f(x) = 8x^2?
  2. What is the derivative of g(x)+h(x)g(x) + h(x)?
  3. How would you factor 3x2+24x+213x^2 + 24x + 21?
  4. What is the range of h(x)g(x)\frac{h(x)}{g(x)}?
  5. How does the product of two functions affect their domains?

Tip:

When factoring quadratic expressions, always check if there's a common factor before applying other factoring techniques.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Algebra
Polynomials
Factoring
Rational Functions
Domain of Functions

Formulas

Polynomial addition: (a + b) + (c + d) = a + c + b + d
Polynomial multiplication: (a * b) = ab
Factoring quadratics: ax^2 + bx + c = (px + q)(rx + s)
Domain restriction: Set denominator ≠ 0

Theorems

Basic Polynomial Operations
Quadratic Factoring Theorem
Domain Restrictions for Rational Expressions

Suitable Grade Level

Grades 9-10