a) (x - 3) ( x + 3) - ( 3x + 2)2
=> x2 - 32 - (9x2 + 12x + 4)
=> x2 - 9 - 9x2 - 12x - 4
=> - 8x2 - 12x - 13
b) (x + 1) ( x- 1) - (2x - 5)2
=> x2 - 1 - (4x2 - 20x + 25)
=> x2 - 1 - 4x2 + 20x - 25
=> - 3x2 + 20x - 26
c) (x - 3 )2 - (x + 2)2 - (x + 6 ) (x - 5)
=> x2 - 6x + 9 - ( x2 + 4x + 4) - ( x2 - 5x + 6x - 30)
=> x2 - 6x + 9 - x2 - 4x - 4 - x2 + 5x - 6x + 30
=> - x2 - 11x + 35
d) (x + 2 )3 - (x - 2)2
=> x3 + 6x2 + 12x + 8 - (x2 - 4x + 4)
=> x3 + 6x2 + 12x + 8 - x2 + 4x - 4
=> x3 + 5x3 + 16x + 4
a)
\(=x^2-3^2-\left(\left(3x\right)^2+2.3x.2+2^2\right)\)
\(=x^2-9-\left(9x^2+12x+4\right)\)
\(=x^2-9-9x^2-12x-4\)
\(=-8x^2-12x-13\)