Answer:
42
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Step-by-step explanation:
Step 1: Define
2x³ - x² - 4x + 9
x = 3
Step 2: Evaluate
- Substitute in x:                    2(3)³ - 3² - 4(3) + 9
- Exponents:                          2(27) - 9 - 12 + 9
- Multiply:                               54 - 9 - 12 + 9
- Subtract:                              45 - 12 + 9
- Subtract:                              33 + 9
- Add:                                     42