Step: Find the sum of given expressions
We need to add (4a2+5b2−6ab),(3ab),(6a2−2b2) and (4b2−5ab)
=(4a2+5b2−6ab)+(3ab)+(6a2−2b2)+(4b2−5ab)
=(4a2+6a2)+(5b2−2b2+4b2)+(−6ab+3ab−5ab) [Grouping like terms]
=10a2+(3b2+4b2)+(−3ab−5ab)
=10a2+7b2−8ab
Hence, the answer is 10a2+7b2−8ab.