m=3+√5
n=1-2√5
m+n=3+√5 +1-2√5=4-√5
n-m=1-2√5-3-√5=-2-3√5
m/n=(3+√5)/(1-2√5)=(3+√5)(1+2√5)/(1-2√5)(1+2√5)=
(3-6√5+√5-2 razy5)/(1-4 razy5)= (-7-5√5)/(-19)=(7+5√5)/19
m²/(2n-m)=(3+√5)²/[2(1-2√5)-3-√5]=
(9+6√5+5)/(2-4√5-3-√5)= (6√5+14)/(-1-5√5)=
(6√5+14)(-1+5√5)/(-1-5√5)(-1+5√5)=
(-6√5-14+30 razy 5+5 razy14√5)/(1-125)=
(64√5+136)/(-124)=8(8√5+17)/(-4 razy 31)=-2(8√5+17)/31
