-b(b+5)-(b-6)(b+6)= -b^2- 5b - (b^2-36) = -b^2-5b-b^2+36= -2b^2-5b+36
=-b*2(b в квадрате)-5b-b*2+36=-2b*2-5b+36
-b(b+5)-(b-6)(b+6)= -b^2- 5b - (b^2-36) = -b^2-5b-b^2+36= -2b^2-5b+36
=-b*2(b в квадрате)-5b-b*2+36=-2b*2-5b+36