Expanding single brackets

Example: Expand 3(2x + 5) using the grid method

Draw a grid with one row and two columns, since we have one term outside the brackets (3) and two terms inside the brackets (2x and 5):

\times2x2x
3

Although it’s not necessary to write the multiplication sign in the top-left it can help remind us that we are multiplying each row term by each column term.

Now, multiply each term inside the brackets by the term outside the brackets:

\times2x5
36x15

Add the terms in the middle of the grid together to get the final answer:

flashcards

QuestionAnswer
What is the grid method for expanding 3(2x + 5)?Draw a grid with one row and two columns; multiply the outside term (3) by each inside term (2x and 5); then add the results: 6x + 15.
Why might you write a multiplication sign in the top-left of the grid?It can help remind you that you are multiplying each row term by each column term.
After multiplying in the grid method, how do you get the final expanded expression?Add the terms in the middle of the grid together.