<PRE><B>Question 763202</B>
1)  (x + 5)(x - 6) - (x-7)(x+8)
(x^2 + x - 30) - (x^2 + x - 56)
 x^2 + x - 30 - x^2 - x + 56
     = 26
2) (1/4x-3)(1/4x+3) 
   1/ 16x^2 - 9
   
3)  (x+1)(x+4)(x-1)(x-4) 
    (x^2 + 5x + 4( (x - 1)(x - 4)
    (x^3 + 5x^2 + 4x - x^2 - 5x - 4)(x - 4)
    (x^3 + 4x^2 - x - 4)(x - 4)
    (x^4 + 4x^3 - x^2 - 4x - 4x^4 - 16x^2 + 4x + 16
    -3x^4 + 4x^3 - 17x^2 + 16
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