Verified answer

a =(9-2x)²

a = 81-36x+4x²

b =x(5-x) -(x+2)²

b = 5x-x²-(x²+4x+4)

b= 5x-x²-x²-4x-4

b =-2x²+x-4

c =(7x+5)(7x-5)

c = 49x²-35x+35x-25

c =49x²-25

d =x(2-x) -(x+3)²

d = 2x-x²-(x²+6x+9)

d =2x-x²-x²-6x-9

d = -2x²-4x-9