Expansion Of Algebraic Expressions (in brackets) 4 examples, with Animated Rectangle
Think of algebraic terms as areas of rectangles
For example would be the area of a rectangle with length and breadth .
When the rectangle is divided into two, along its length , such that one has the length while the other has the length then there are two rectangles.
The areas of the rectangles and respectively.
Hence the original area is equal to the sum of areas of the two rectangles .
The first example 3(5 + 2) shows two rectangles, one with length of 5 units and the other with length of 2 units, both having breadth of 3 units.
The areas of each rectangle is 3 x 5 = 15 square units and 3 x 2 = 6 square units.
Total area is 15+6 = 21 square units.
Now 3(5+2) is also 3 x 7 = 21 square units.
Hence using the area of rectangle as a model for multiplication of algebraic variables can provide a visual understanding of the expansion of algebraic expression in brackets.