Question

24
17
57
19
18 1
-;
x-
3x+1
35
-
x
9
. Determinați numerele naturale x pentru care sunt definite fracțiile:
12- x' 2x - 2 x(x - 1) (x+7)(x-2)​

Answer 1

x∈ℕ

18/(x-3) => (x-3)|18 => x-3∈{1,2,3,6,9,18}

x∈{4,5,6,9,12,21}

1/(x+1) => (x+1)|1 => x+1∈{1} /-1

=> x=0

35/x => x|35 => x∈{1,5,7,35}

24/(12-x) => (12-x)|24 => 12-x∈{1,2,3,4,6,8,12,24}

x∈{0,4,6,8,9,10,11,12}

17/(2x-2) => (2x-2)|17 => 2x-2∈{1,17}

2x∈{3,19}

x∈{3/2;19/2}

dar: x∈ℕ => x∈Ø