a) = x²-6x+9+x²+2x+1-4x²+1 = -2x²-4x+11
b) = 4x²+20x+25-9x²-30x-25+4x²-49 =-x²-10x-49
c) = x²+8x+16-4x²+9+4x²+4x+1 = x²+12x+26
d) = 4x²+12x+9-2(x²-9)+x²-36-2x+1 = 5x²+10x+10-2x²+18 = 3x²+10x-8
e) = 9x²-1-9x²-24x-16+2(9x²-6x+1) = -24x-17+18x²-12x+2 = 18x²-36x-15
f) 9-6x+4x²-4x²+25+4(x²-4x+4) = -6x+36+4x²-16x+16 = 4x²-28x+50
g) 16x²-24x+9-3(x²-1)-2(4x²-28x+49) = 16x²-24x+9-3x²+3-8x²+56x-98 = 5x²+32x-86
