[tex] a) -4x=-12\\x=\frac{-12}{-4}\\x=3\\ [/tex]
are in N solutia 3. (x=3∈N)
[tex] b) 2x-1=-9\\2x=-9+1\\2x=-8\\x=\frac{-8}{2}\\x=-4 [/tex]
nu are in N solutia - 4 (x= - 4 ∉N)
[tex] 2x-1=-9\\2x=-9+1\\2x=-8\\x=\frac{-8}{2}\\x=-4\\ [/tex]
are in Z solutia - 4 (x= -4 ∈Z)
[tex] -3x+5=x+17\\ -3x-x=17-5\\-4x=12\\x=\frac{12}{-4}\\x=-3 [/tex]
nu are in N solutia - 3 (x= - 3∉N)
