Factorize the Expression: 13abcd + 26ab Step-by-Step

To solve this problem, we'll follow these steps:

• Step 1: Identify the greatest common factor (GCF) of the terms in the expression.
• Step 2: Factor out the GCF from the expression.
• Step 3: Simplify the expression inside the parentheses.

Step 1: Determine the GCF of the terms $13abcd$ and $26ab$.
The GCF of the coefficients $13$ and $26$ is $13$.
The variables $a$ and $b$ are common in both terms, so the GCF of the variables is $ab$.

Therefore, the GCF of the expression is $13ab$.

Step 2: Factor out the GCF.
Factor $13ab$ from each term in the expression:
$13abcd + 26ab = 13ab(cd) + 13ab(2)$

Step 3: Simplify to obtain the final factorised expression:
$13ab(cd + 2)$

Therefore, the factorised form of the expression is $13ab(cd + 2)$.

Among the given choices, this corresponds to choice 2: $13ab(cd+2)$.