Answer:
A. [tex]\displaystyle f^{-1}(x) = 7 - 21x[/tex]
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Distributive Property
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtraction Property of Equality
Algebra I
- Terms/Coefficients
- Functions
- Function Notation
- Inverse Functions
Step-by-step explanation:
Step 1: Define
Identify
[tex]\displaystyle f(x) = \frac{1}{3} - \frac{1}{21}x[/tex]
Step 2: Find inverse
- Rewrite: [tex]\displaystyle y = \frac{1}{3} - \frac{1}{21}x[/tex]
- Swap: [tex]\displaystyle x = \frac{1}{3} - \frac{1}{21}y[/tex]
- [Subtraction Property of Equality] Isolate y term: [tex]\displaystyle x - \frac{1}{3} = -\frac{1}{21}y[/tex]
- [Multiplication Property of Equality] Isolate y: [tex]\displaystyle -21(x - \frac{1}{3}) = y[/tex]
- [Distributive Property] Distribute -21: [tex]\displaystyle 7 - 21x = y[/tex]
- Rewrite: [tex]\displaystyle f^{-1}(x) = 7 - 21x[/tex]