X^2 - 7x - 14 = 0
D = 49 + 4*14 = 49 + 56 = 105
x1 = (7 + √105)/2;
x2 = ( 7 - √105)/2
x1 + x2 = (7 + √105 + 7 - √105)/2 = 14/2 = 7
24.04 ляляляля без 20 символов не отправить
(x(x-2y))/((x-2y)^3)=
=x/((x-2y)^2
x/((x-2y)^2)-1/(x-2y)=
=(x-(x-2y))/(x-2y)^2=
=(2y)/(x-2y)^2
=((√2m)²-(√5n)²)/(√2m+√5n)=(√2m-√5n)·(√2m+√5n)/(√2m+√5n)=(√2m-√5n).