Answer:
(5a+4c)(2a-b)
Step-by-step explanation:
Given the expression:

First, group the expression into two:

• In the first group, 5a is a common factor.
,
• In the second group, 4c is a common factor.
Factor these out by dividing each term by the GCF of each group.

Since the terms inside the brackets are the same, combine:

CHECK
To check if your result is correct in cases like these, expand as follows:

Our result is the same as the original question, hence, the work is correct.