Question

Subtract the sum of (3a square-2a-5) and (a square -5a+7) from the sum of (5a square -9a+3) and (2a square -a-1).

Answer 1

Sum of ( 5a²-9a+3+2a²-a-1 )
= 7a²-10a+2. ( i )

And sum of ( 3a²-2a²-5+a²-5a+7 )
= 4a²-7a+2. ( ii )
Subtract ( ii ) - ( i )
= ( 7a²-10a+2 ) - ( 4a²-7a+2 )
= ( 7a²-10a+2 - 4a²+7a-2 )
= ( 3a²-3a )
= 3a (a-1)