Question

Determinati multimile: A={x|x apartine N si (x-5)|3x+18)}

Answer 1

x-5|x-5     inmultesc cu 3
x-5|3(x-5)
     x-5|3x-15
dar x-5 | 3x+18
rezulta ca x-5 | 3x+18-(3x-15) ⇒
x-5|33
x-5∈{1,3,11,33}
x∈{6,8,16,38}
A= {6,8,16,38}