Opening Brackets and Enclosing in Brackets
In this lesson, we'll learn two important skills: how to open brackets (remove parentheses) and how to enclose terms in brackets (the reverse operation). These skills are essential for simplifying algebraic expressions!
📖 What is Opening Brackets?
Opening brackets (also called expanding brackets) means:
- Removing parentheses from an expression
- Applying the sign in front of brackets to ALL terms inside
- Simplifying the expression
Russian vocabulary:
Раскрытие скобок = Opening/Expanding brackets
Раскрытие скобок = Opening/Expanding brackets
🔄 What is Enclosing in Brackets?
Enclosing in brackets is the reverse operation:
- Grouping terms together inside parentheses
- Placing a sign before the brackets
- Adjusting signs inside if needed
Russian vocabulary:
Заключение в скобки = Enclosing in brackets
Заключение в скобки = Enclosing in brackets
⭐ Rule 1: Plus Sign Before Brackets
The Rule:
When there's a + (plus) before brackets, simply remove the brackets. All signs inside stay the SAME!
Formulas:
+(a + b) = a + b
+(a − b) = a − b
Think of it this way: Plus doesn't change anything! It's like multiplying by +1.
Interactive visualization — available in the full lesson