Algebra-1

Question Analysis
This question tests the ability to factor a multivariable polynomial using the grouping method, which is a key skill in Algebra-1.

Key Concept Explanation
Factoring by grouping involves dividing the polynomial into groups, extracting the greatest common factor (GCF) from each group, and then factoring out the common binomial factor.

Step-by-step Solution
Step 1: Group the terms into two pairs
Group the first two terms and the last two terms:
Step 2: Factor out the GCF from each group
From the first group , the GCF is 5ab:
From the second group , the GCF is 10:
This gives: