how could you use the gcf and the distributive property to express the sum of 63 + 81?
a 7(9 + 13)
b 7(9 + 3)
c 3(21 + 27)
d 9(7 + 9)
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.
63 / 9 = 7
81 / 9 = 9
Write the sum as:
9 ( 7 + 9 )
Check result.
9 ( 7 + 9 ) = 9 • 7 + 9 • 9 = 63 + 81