PrerequisitesPrerequisite

Expanding three parentheses - using the grid method

Use a multiplication grid to expand three parentheses in two stages.

  • Write the terms from one factor down the side and the terms from the other across the top.
  • Keep the positive or negative sign with each term.
  • Multiply each row heading by each column heading to fill every cell.
  • Add the cell products, then collect like terms.

Example 1

Expand and simplify using the grid method.

1Expand the first two parentheses.

Add the products and collect like terms.

2Multiply by the remaining linear parenthesis.

Add the products and collect like terms.

Example 2

Multiply out the parentheses using a grid, then collect like terms.

1Expand the first two parentheses.

Add the products and collect like terms.

2Multiply by the remaining linear parenthesis.

Add the products and collect like terms.

Remember
For three parentheses, finish the first grid before multiplying by the third parenthesis.

Your turn

5 practice questions
Question 1

Expand and simplify using the grid method.

Check answer

1Expand the first two parentheses.

Add the products and collect like terms.

2Multiply by the remaining linear parenthesis.

Add the products and collect like terms.

Question 2

Expand and simplify using the grid method.

Check answer

1Expand the first two parentheses.

Add the products and collect like terms.

2Multiply by the remaining linear parenthesis.

Add the products and collect like terms.

Question 3

Expand and simplify using the grid method.

Check answer

1Expand the first two parentheses.

Add the products and collect like terms.

2Multiply by the remaining linear parenthesis.

Add the products and collect like terms.

Question 4

Expand and simplify using the grid method.

Check answer

1Expand the first two parentheses.

Add the products and collect like terms.

2Multiply by the remaining linear parenthesis.

Add the products and collect like terms.

Question 5

Expand and simplify using the grid method.

Check answer

1Expand the first two parentheses.

Add the products and collect like terms.

2Multiply by the remaining linear parenthesis.

Add the products and collect like terms.