Răspuns :
2x+7 = 43+x => 2x-x = 43-7
x = 36 ∈ N ;
84 : (x - 3) = 12 => x - 3 = 84 : 12
x = 7 + 3
x = 10 ∈ N ;
x = 36 ∈ N ;
84 : (x - 3) = 12 => x - 3 = 84 : 12
x = 7 + 3
x = 10 ∈ N ;