Răspuns :
[tex]a)5x - 125 = 0[/tex]
[tex]5x = 125 \: | \div 5[/tex]
[tex]x = 25 \: \in \: \mathbb{N}[/tex]
[tex]b)3x + 7 = 0[/tex]
[tex]3x = - 7[/tex]
[tex]x =- \frac{7}{3} \: \notin \: \mathbb{N}[/tex]
[tex]5x = 125 \: | \div 5[/tex]
[tex]x = 25 \: \in \: \mathbb{N}[/tex]
[tex]b)3x + 7 = 0[/tex]
[tex]3x = - 7[/tex]
[tex]x =- \frac{7}{3} \: \notin \: \mathbb{N}[/tex]
a) 5x - 125 = 0
5x = 125
x = 125 : 5
x = 25 ∈ N
b) 3x + 7= 0
3x = -7
x = -7 : 3
x = -7/3 ∉ N
5x = 125
x = 125 : 5
x = 25 ∈ N
b) 3x + 7= 0
3x = -7
x = -7 : 3
x = -7/3 ∉ N