Consider the expression 63 + 81.
How can you use the distributive property and the GCF to find an equivalent expression? Explain how you can check your answer.
The GCF of 63 and 81 is 9, so you can use that as the factor outside of the parentheses. Divide both numbers by 9 and write the sum as 9(7 + 9). You can check that the sum 63 + 81 is the same as the product 9(7 +9).