a) =4x^2−33x+35−(2x−7)^2
=4x^2−33x+35−(4x^2−28x+49)
=4x^2−33x+35−4x^2+28x−49
=−33x+35+28x−49
=−5x+35−49
=−5x−14
b)=18x/x(x−3)(x+3) - 2−x/x+3 + 3/3−x
=18/(x-3)(x+3) - 2-x/x+3 + 3/3-x
=18/(x-3)(x+3) - (2−x)(x−3)/(x−3)(x+3) + 3/3−x
=18−(2−x)(x−3)/(x−3)(x+3) + 3/3-x
=18−2x+6+x^2−3x/(x−3)(x+3) + 3/3-x
=24+x^2−5x/(x−3)(x+3) + 3/3-x
=24+x^2−5x/(x−3)(x+3) + 3(−1)(x+3)/(x−3)(x+3)
=24+x^2−5x+3(−1)(x+3)/(x−3)(x+3)
=24+x^2−5x−3x−9/(x−3)(x+3)
=15+x^2−8x/(x−3)(x+3)
=(x-5)(x-3)/(x−3)(x+3)
=x-5/x+3
c)=(5x−15)(x^2+2x+1)/(4x-4)-(9x-x^2)
=5(x−3)(x+1)^2/4(x−3)-(x−1)(-x-3)
=5(x+1)^2/4(x−1)(−x−3)
=5x^2+10x+5/−4x^2−8x+12