Math Problem Statement

For f(x)=3x2 – x+5, 2f(–3) – f(4)

Solution

To solve the expression 2f(3)f(4)2f(-3) - f(4) for the function f(x)=3x2x+5f(x) = 3x^2 - x + 5, follow these steps:

Step 1: Evaluate f(3)f(-3)

Substitute x=3x = -3 into the function: f(3)=3(3)2(3)+5=3(9)+3+5=27+3+5=35f(-3) = 3(-3)^2 - (-3) + 5 = 3(9) + 3 + 5 = 27 + 3 + 5 = 35

Step 2: Evaluate f(4)f(4)

Substitute x=4x = 4 into the function: f(4)=3(4)24+5=3(16)4+5=484+5=49f(4) = 3(4)^2 - 4 + 5 = 3(16) - 4 + 5 = 48 - 4 + 5 = 49

Step 3: Compute 2f(3)f(4)2f(-3) - f(4)

Now use the values found in Steps 1 and 2: 2f(3)f(4)=2(35)49=7049=212f(-3) - f(4) = 2(35) - 49 = 70 - 49 = 21

Final Answer:

2f(3)f(4)=212f(-3) - f(4) = 21

Would you like any additional details on these steps?

Here are five related questions:

  1. How would you find the derivative of f(x)=3x2x+5f(x) = 3x^2 - x + 5?
  2. What happens to the expression if f(x)f(x) changes to a different quadratic function?
  3. How would the process change if you were given 3f(3)2f(4)3f(-3) - 2f(4)?
  4. How do you solve for xx when f(x)=0f(x) = 0 for this function?
  5. Can you generalize 2f(a)f(b)2f(a) - f(b) for any values of aa and bb?

Tip: Always substitute values carefully and simplify step by step to avoid mistakes.

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Math Problem Analysis

Mathematical Concepts

Algebra
Quadratic Functions
Function Evaluation

Formulas

f(x) = 3x^2 - x + 5
Function Evaluation: f(a)
Basic Arithmetic Operations

Theorems

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Suitable Grade Level

Grades 9-10