42
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction
Left to Right
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) + 9Exponents:              2(27) - 9 - 12 + 9Multiply:                54 - 9 - 12 + 9Subtract:                45 - 12 + 9Subtract:                33 + 9Add:                   42