Răspuns:
10'=5+1/5
12'=5+1/7
7'=5+1/2
Explicație pas cu pas:
x compus y=(x-5) (y-5)+5
legea e comutativa si aasociatuiva, num acrezi, poti sa verifici! ::)0
xcompus e= x= (x-5) (e-5)+5
(x-5)= (x-5)(e-5)
pt x≠5, x-5=1...e=6
xcompus x'=6=(x-5) (x'-5)+5
(x-5)(x'-5)=1
x'=5+1/(x-5) toate au simetric in Q, mai putin 5
10'=5+1/5
12'=5+1/7
7'=5+1/2
verificare
7compus 7'= (7-5)(5+1/2-5)+5=2*1/2+5=1+5=6
adevarat, bine rezolvat