Answer:
15
General Formulas and Concepts:
Pre-Algebra
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtraction Property of Equality
Explanation:
Step 1: Define
Identify
5a - 10b = 45
b = 3
Step 2: Solve for a
- Substitute in b [Equation]: 5a - 10(3) = 45
- Multiply: 5a - 30 = 45
- [Addition Property of Equality] Add 30 on both sides: 5a = 75
- [Division Property of Equality] Divide 5 on both sides: a = 15