П/6+П/3=п/2...................................
(а-1/a^2)*(ax-a/a-1)+(x-1/2a)=((a-1)*a(x-1)/a^2*(a-1))+((1-x)/2a)=((x-1)/a)+((1-x)/2a)=
=((2x-2)/2a)+((1-x)/2a)=((2x-2+1-x)/2a)=x-1/2a
"/"-дробь
task/29424356 ---------------------
49b²+14b +1 =(7b)² +2*7b*1 +1²= (7b+1)² * * * (7b+1) (7b+1) * * * --- uz⁶ +uy⁶ - yz⁶ - y⁷ =u(z⁶ +y⁶) - z(z⁶ +y⁶) = (u- z)(z⁶ + y⁶) .