Question

Buna seara! Ma puteti ajuta cu aceasta problema?

Answer 1

x=6n-7 /2n+1 dar deoarece x∈Z <=> 6n-7 /2n+1 ∈Z <=> 2n+1 /6n-7 dar 2n+1 /2n+1 <=> 2n+1 /6n+3 => 2n+1 /10 si n∈Z => 2n+1∈{-10;-5;-2;-1;1;2;5;10}. Observam ca 2n+1-numar intreg impar => 2n+1∈{-5;-1;1;5} => 2n∈{-6;-2;0;4} => n∈{-3;-1;0;2} ,de unde obtinem x∈{-7;5;13;2} => A={-7;2;5;13;} .