Question

Precizati numerele mulțimii:
A = {x/7/2x+1 € N*}


( 7/2x+1 = 7 supra 2x+1)

Answer 1

$\frac{7}{2x + 1} = 0 \\ 2x + 1 = 7 \\ 2x = x = 3$

Answer 2

7/(2x+1) apartine lui N*
=> 2x+1 ={1,7}
2x+1=1 <=> 2x=0, deci x=0
2x+1=7<=> 2x=6, deci x=3
A={0,3}