Question

Simetricul lui 10, 12, 7 avand legea de compozitie x*y=xy-5x-5y+30

Answer 1

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