1. find their GCF
2. The factors of 56 are 1, 2, 4, 7, 8, 13, 28, and 56 .
And the factors of 64 are 1, 2, 4, 8, 16, 32, and 64 .
3.Find the common factors which are 1, 2, 4, and 8 .
The greatest factor is 8 .
4. divide 56÷8=7
divide 64÷8 = 8
8×7=56 8×8=64 56+64
56+64 = 8×(7+8)
56+64 = 120
8× (7+ 8) = 8×15
= 120 =120