👤

Dau coroana
(xy+yx):11



Răspuns :

x+y=?
xy+yx-patrat perfect
xy= 10x+y
yx=10y+x
xy+yx= 11x+11y=11(x+y)
 
xy+yx= 11(x+y)
x+y=11

11x11=121 -patrat perfect