Question

aflati x apartine nr naturale,stiind ca 4/(2x-6) si (2x-6)/4

Answer 1

(2x-6)|4 inseamna sa gasim divizorii lui 4
D4={-4,-2,-1,1,2,4}
2x-6=-4 x=1
2x-6=-2 ,x=2
2x-6=-1 ∉N
2x-6=1∉N
2x-6=2,x=4
2x-6=4,x=5
x={1,2,4,5}
4|(2x-6)
2x-6 terbuie sa fie multipli de 4
M4={0,4,8,12,16,20.............}
2x-6=0,x=3
2x-6=4,x=5
2x-6=8,x=7 
x={3,5,7..............}
solutia este data de intersectia celor doua 
S: x={5}