To rewrite \( 12 + 18 \) using their greatest common factor (GCF) and multiplication, we first need to find the GCF of 12 and 18.
The GCF of 12 and 18 is 6. We can factor both numbers:
\[ 12 = 6 \times 2 \] \[ 18 = 6 \times 3 \]
Now, we can rewrite the sum \( 12 + 18 \):
\[ 12 + 18 = (6 \times 2) + (6 \times 3) \]
We can factor out the GCF (6):
\[ 12 + 18 = 6(2 + 3) \]
So, rewriting \( 12 + 18 \) using their GCF and multiplication gives us:
\[ 6(2 + 3) \]