Question

AJUTOOOOOR ESTE URGEEEENT!!!!
DAU 50 DE PUNCTE SI CORONITAAA​

Answer 1

Răspuns:

Explicație pas cu pas:

1) a) -7/11 ∈ Q = adevarat

  b) -7/11 ∈ Z = fals

  c) +26/13 ∈ Q₊ = adevarat

  d) +26/13 = 2 ∈ N = adevarat

2) A = {-1/6 ; +9/3 ; -25/10 ; +49/7 ; -23/23 ; +102/25}

A ∩ (Q-Z) = ?

-1/6 ∈ Q ; +9/3 = 3 ∈ Q;Z ; -25/10 = -5/2 ∈ Q ;

+49/7 = 7 ∈ Q,Z ; -23/23 = -1 ∈ Q,Z ; +102/25 ∈ Q

A ∩ (Q-Z) = {-1/6 ; -25/10 ; +102/25}

3) a) ¹⁰⁾-11/6 si ³⁾-11/20 <=> -110/60 si -33/60

-110/60 < -33/60  => -11/6 < -11/20

   b) -7/23 si 19/23  => -7/23 < 19/23

   c) ⁷⁾-5/3 si ³⁾-6/7 <=> -35/21 si -18/21 =>

-35/21 < -18/21 => -5/3 < -6/7

  d) -15/4 si 16/5  => -15/4 < 16/5

4) 21,5342  ; 21,5(342) ; 21,53(42) ; 21,534(2)

21,5342  = 21,53420000...

21,5(342) = 21,5342342...

21,53(42) = 21,534242...

21,534(2) = 21,534222...

21,5342 < 21,534(2) < 21,5(342) < 21,53(42)

5) a) IxI = 5/9  => x = 5/9  ;

                           -x = 5/9 => x = -5/9

  b) I⁴⁾x-11/4I = 1/2  <=> I (4x-11)/4I = 1/2 <=>

I 4x-11 I = 4/2 = 2

Pentru x ≥ 11/4  => 4x-11 = 2 => x = 13/4

Pentru x < 11/4 => -4x+11 = 2 => x = 9/4

6) A = {x ∈ Z  I  -5 ≤ (3x+2)/2 < 5}

-5 ≤ (3x+2)/2 < 5 <=> -10 ≤ 3x+2 < 10 <=>

-12 ≤ 3x < 8 I : 3  => -4 ≤ x < 8/3  =>

A = {-4 ; -3 ; -2 ; -1 ; 0 ; 1 ; 2}

cardA = 7