Question

Rezolvati in Z:
4x-5y=25 si IxI<12.

Answer 1

|X|<12 ⇒ x∈{-11,-10,-9,-8,-7,-6,-5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10,11}
4x-5y=25
daca x=-11
4.(-11)-5y=25
-44-5y=25
5y=-69
y=-69/5∉Z
daca x=-10
-40-5y=25
5y=-65
y=-13∈Z avem perechea (-10,-13)

pt x=-5⇒5y=-20-25=-45
y=-9⇒perechea (-5,-9)
pt x=0⇒5y=-25⇒y=-5 
perechea (0,-5)
pt x=5⇒5y=20-25=-5⇒y=-1
perechea(5,-1)
pt x=10⇒5y=40-25=15⇒y=3
perechea (10,3)