Răspuns :
X1=169:13 ;
X1=13;
X:13•13=169;
X2=169:13•13;
X2=169;
X=2013:2013+2012;
X=1+2012;
X=2013
13x =169
x=169:13
x=13
2013:(x-2012)=2013
(x-2012)=2013:2013
x-2012=1
x=2012+1
x=2013
x=169:13
x=13
2013:(x-2012)=2013
(x-2012)=2013:2013
x-2012=1
x=2012+1
x=2013