1) 3y2 ((2y-1) + y + 1) - y (1 - y + y2) - y2 + y =

2) a + (2a-c) - a (4a+2) - ((a+3a) (-a) - c) =

3) ax (-x-2) + x2 (3-a) - a (-2 (-x) 2 - 2x) =

4) 2 (X+1) (X2-X+1) - (2X-1) (x2+3x) - (x-1) (1-5x)

1) = 3y2 (2y-1+y+1) - y (1-y+y2) - y2+y = 6y3-3y2+3y3+3y2-y+y2-y3-y2+y = 6y3-y3+3y3 = 4y3

2) = a+2a-c-4a2-2a - (-a2-3a2-c) = a+2a-c-4a2-2a+a2+3a2+c = a

3) = - ax2-2ax+3x2-ax2-a (2x2-2x) = - ax2-2ax+3x2-ax2-2ax2+2x = 2x-4ax2-2ax+3x2

4) = 2 (x3+1) - 2x3-5x2+3x+5x2-4x+1 = 2x3+2-2x3-5x2+3x+5x2-4x+1 = 1-x