BRACKETS

Definition Of Brackets

Brackets can be defined as a pair of symbols used to group things together.

More About Brackets

Brackets can be classified into four types based on their usage
Parentheses or round brackets, denoted by '( )', is generally used to define the different precedence of numbers in a mathematical expressionBox brackets or square brackets: Apart from mathematical expression, '[ ]' square brackets are also used to represent the numbers in interval
Curly brackets or braces, denoted by '{ }', are used to delimit sets
Angle brackets or chevrons, denoted by '<>', are used to enclose highlighted material to denote dialogue that is thought instead of spoken

Video Examples: How to do Algebra Part 1 1 Expanding Brackets 1

Examples of Brackets

a(x + y) = ax + ay
3ab²c(2a + 3ab - 5bc² + 1) 
= 3ab²c × 2a + 3ab²c × 3ab - 3ab²c × 5bc² + 3ab²c × 1
= 16 + (4 × 7) − 4 
= 16 + 28 - 4 
= 44 - 4 = 40

Solved Example on Brackets

Ques: What is the value of the expression below? 20 - (5 × 4) + 4

Choices:

A. 2
B. 3
C. 1
D. 4
Correct Answer: D

Solution:

Step 1: The order of operation for the expression is, operation within grouping symbol first, addition next, and then subtraction, from left to right
Step 2: 20 - (5 × 4) + 4 [Original expression.] 
Step 3: = 20 - 20 + 4 [Do the operation within the grouping symbol.] 
Step 4: = 24 - 20 [Add 20 and 4.] 
Step 5: = 4 [Subtract 20 from 24.] 
Step 6: The value of the given expression is 4.