Adding:
(3x2 − 5x + 2) + (−5x2 − 8x + 6)
Rearranging and collecting the like terms:
(3-5)x2 +(− 5-8)x + 2 +6
= -2x2 − 13x + 8
Subtract 4x2 − 9x + 7 from -2x2 − 13x + 8.
Change the sign of each term of the expression that is to be subtracted and then add.
Term to be subtracted = 4x2 − 9x + 7
Changing the sign of each term of the expression gives -4x2 + 9x - 7.
On adding:
( -2x2 − 13x + 8 )+(-4x2 + 9x - 7 ) = -2x2 − 13x + 8 -4x2 + 9x - 7
= ( -2-4)x2 +(−13+9)x + 8 -7
= -6x2 − 4x + 1