Question

Det x apartine Z A.I:

$\frac{15}{2x + 3}$
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Answer 1

2x+ 3 trebuie sa divida pe 15 ca sa aiba sens fractia, x apartine Z

Deci D15 = {0,1,3,5,15}

2x+3 = 0 => 2x =  -3 => x = -3/2 nu apartine Z

2x+3 = 1 => 2x=  -2 => x = -1 apartine Z

2x+3  = 3=> 2x = 0=> x= 0 apartine Z

2x+3 =5=> 2x = 2=> x= 1 apartine Z

2x+3 =15=> 2x= 12 => x= 6 aaprtine Z

deci x={-1,0,1,6}