76 баллов, решение на 7 минут, сам в не разумею, решений

(c + 4)(c - 4)(c + 16) - (c - 8) = (c - 16)(c + 16) - (c - 8) =
= c - 256 - c + 16c - 64 = 16c - 320


(2b - 1) - (b + 2) = (2b - 1 + b + 2)(2b - 1 - b - 2) = (3b + 1)(b - 3)

(2x + 5)(x - 6) + 2(3x + 2)(3x - 2) = 5(2x + 1) + 11
2x - 12x + 5x - 30 + 2(9x - 4) = 5(4x + 4x + 1) + 11
2x - 7x - 30 + 18x - 8 - 20x - 20x - 5 - 11= 0
- 27x -54 = 0
x + 2 = 0
x = - 2

(c+4)(c-4)(c+16)-(c-8)=(c-16)(c+16)-(c-8)=
=c-256-c+16c-64=16c+320=16*(-1/4)-320=16*(1/16)-320=1-320=-319.

(2b-1)-(b+2)=4b-4b+1-b-4b-4=3b-8b-3=3*(b-3)*(b+1/3).

(2x+5)(x-6)+2*(3x+2)(3x-2)=5*(2x+1)+11
2x-7x-30+18x-8=20x+20x+5+11
20x-7x-38=20x+20x+16
-7x-38=20x+16
27x=-54
x=-2.