To factor the expression \( 2a^3b + 6a^2b^2 \), we first need to identify the greatest common factor (GCF).
The GCF of the coefficients (2 and 6) is 2.
For the variables:
- The GCF of \( a^3 \) and \( a^2 \) is \( a^2 \).
- The GCF of \( b \) and \( b^2 \) is \( b \).
Therefore, the GCF of the entire expression is \( 2a^2b \).
Now, we can factor out \( 2a^2b \) from the original expression:
\[ 2a^3b + 6a^2b^2 = 2a^2b(a + 3b) \]
So, the correct rewritten expression by factoring out the GCF is:
2a^2b(a + 3b)