Problem : Simplify (4x4 +3x6 -23x5 +9) + (12x - 4x4 +22x5).

3x6 - x5 + 12x + 9

Problem : Simplify (8x2 +2xy - 15y + y2) + (6y - 7x + 2xy - 3x2).

5x2 + y2 + 4xy - 7x - 9y

Problem : Simplify (- 2x6 + x4 +18x3 +11) + (3x5 -2x4 -18x3 - 12x + 9)

-2x6 +3x5 - x4 - 12x + 20

Problem : What monomial does the represent?
(4x3 + x2 - ) + (- 5x3 +6x2 +13x + 4) = - x3 +7x2 + x + 4

= 12x

Problem : Simplify (7x3 +4x2 -11x + 8) - (3x2 - 2x - 1).

7x3 + x2 - 9x + 9

Problem : Simplify (- 4x4 - x3 +11x2 -2) - (- 4x4 +3x3 +12x2 - 3x + 4)

-4x3 - x2 + 3x - 6

Problem : Simplify (3x6 -12x4 +43x3 -12x + 9) - (3x5 -7x4 -23x3 +18x2 + 12x - 4)

3x6 -3x5 -5x4 +66x3 -18x2 - 24x + 13