Question

Determina x∈N astfel incat : a) 6/x-2∈N   b) 7/x-2∈Z   c) 6/x-2 ∈Z   d 8/x-4 ∈N . Va rog mult ajutati-ma :)  :D 

Answer 1

a)
x-2 apartine divizorilor lui 6
x-2 apartine {1,2,3,6}
x-2=1  x=3
x-2=2  x=4
x-2=3  x=5
x-2=6  x=8
x apartine {3,4,5,8}
b)
x-2 apartine divizorilor lui 7
x-2 apartine {1,7,-1,-7}
x-2=1  x=3
x-2=7  x=9
x-2=-1  x=1
x-2=-7  x=-5
x apartine {3,9,1,-5}

c)
x-2 apartine divizorilor lui 6
x-2 apartine {1,2,3,6,-1,-2,-3,-6}
x-2=1  x=3
x-2=2  x=4
x-2=3  x=5
x-2=6  x=8
x-2=-1  x=1
x-2=-2  x=0
x-2=-3  x=-1
x-2=-6  x=-4
x apartine {3,4,5,8,1,0,-1,-4}

d)
x-4 apartine divizorilor lui 8
x-4 apartine {1,2,4,8}
x-4=1  x=5
x-4=2  x=6
x-4=4  x=8
x-4=8  x=12
x apartine {5,6,8,12}