Question

determinati multima A={xapartineZ|-5 supra 2x+3 apartine lui N

Answer 1

-5/2x+3 apartine N <=> 2x+3 divide -5 =>2x+3 aprtine D-5

D-5={+1;-1;+5;-5}

2x+3=5
2x=5-3
2x=2
x=2÷2
x=1

2x+3=-5
2x=-5-3
2x=-8
x=-8÷2
x=-4

2x+3=1
2x=1-3
2x=-2
x=-2÷2
x=-1

2x+3=-1
2x=-1-3
2x=-4
x=-4÷2
x=-2

A={1;-4;-1;-2}