Răspuns:
Explicație pas cu pas:
a) 7x = 14 => x = 14:7 => x = 2 ∈ N
b) 3x = 5 + (-1)² <=> 3x = 5+1 => 3x = 6 =>
x = 6:3 => x = 2 ∈ Z
c) 2x + 4x = 15 <=> 6x = 15 => x = 15/6⁽³ => x = 5/2 ∈ Q
d) 6x - 3x = 12 => 3x = 12 => x = 12:3 => x = 4 ∈ Q
e) 2x + 5 = 2²+1 <=> 2x +5 = 4+1 => 2x = 5-5 => 2x = 0 =>
x = 0 ∈ N
f) 6x + 3x = -18 => 9x = -18 => x = -18:9 => x = -2 ∉ N =>
ecuatia nu are solutii .
