Question

determinati elementele urmatoarei multimi : B= {x/x∈N, 6/x+2∈Z }

Answer 1

6/x+2∈Z ⇒x+2∈D6=(1,2,3,6,-1,-2,-3,-5)
X+2=1⇒X=-1
X+2=2⇒X=0
X+2=3⇒X=1
X+2=6⇒X=4
X+2=-1⇒-3
X+2=-2⇒-4
X+2=-3⇒-5
X+2=-6⇒-8

Answer 2

x+2 apartine divizorilor lui 6 => x+2€{-6,-3,-2,-1,1,2,3,6} /-2. =>x€{-8,-5,-4,-3,-1,0,1,4}