Recapitulare matematică (3) clasa a VIII-a – semestrul I

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English

MULŢIMI DE NUMERE REALE
▪ Forme de scriere a unui număr real
▪ Reprezentarea numerelor reale pe axa numerelor prin aproximări
▪ Opusul, inversul, modulul unui număr real
▪ Intervale de numere reale
REGULI DE CALCUL ÎN R
▪ Operaţii cu numere reale
▪ Raţionalizarea numitorului

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Question 1 of 10

1. Question
1 points
${(- \frac{3}{4})}^{- 1} =$
- $\frac{3}{4}$
- $\frac{4}{3}$
- $- \frac{4}{3}$
- $- \frac{3}{4}$
Correct

Incorrect
Question 2 of 10

2. Question
1 points
$\sqrt{2} + \sqrt{8} - 3 \sqrt{2} =$
- 1
- $\sqrt{10} - 3 \sqrt{2}$
- 0
- $\sqrt{6}$
Correct

Incorrect
Question 3 of 10

3. Question
1 points
$\sqrt{25^{2} - 3^{2} - 4^{2}} =$
- 0
- $10 \sqrt{6}$
- $\sqrt{{(25 - 3 - 5)}^{2}}$
- 25+3+4
Correct

Incorrect
Question 4 of 10

4. Question
1 points
$\frac{4}{\sqrt{5} + 1} =$
- $\sqrt{5} - 1$
- $\sqrt{5} + 1$
- $\frac{\sqrt{5} + 1}{2}$
- $\frac{\sqrt{5} - 1}{4}$
Correct

Incorrect
Question 5 of 10

5. Question
1 points
$[- 3, 10) \cup (- 10, 3] =$
- $(- 10, 10)$
- $(3, 10)$
- $[- 3, 3]$
- $[3, - 10)$
Correct

Incorrect
Question 6 of 10

6. Question
1 points
Produsul numerelor naturale nenule din intervalul (-3, 3) este:
- 6
- 0
- 2
- 4
Correct

Incorrect
Question 7 of 10

7. Question
1 points
Fie $A = \{- 1; \frac{12}{3}; 0, 45; \sqrt{0}; - \sqrt{\frac{64}{81}}; 6, 7 (89); \sqrt{0, 49}; \frac{- 20}{- 2}\} .$ Dacă $B = A \cap ℕ$ , atunci CardB=
- 3
- 0
- 7
- 8
Correct

Incorrect
Question 8 of 10

8. Question
1 points
$x = \sqrt{5}, y = \frac{1}{\sqrt{5}} \Rightarrow x^{2} + y^{2} = . . .$
- $2 \sqrt{5}$
- 1
- $\frac{6}{\sqrt{5}}$
- $\frac{26}{5}$
Correct

Incorrect
Question 9 of 10

9. Question
1 points
Inversul opusului numărului $- \frac{3}{4}$ este numărul:
- $- \frac{4}{3}$
- $\frac{4}{3}$
- $\frac{3}{4}$
- 4
Correct

Incorrect
Question 10 of 10

10. Question
1 points
$|\sqrt{2} - \sqrt{3}| + |\sqrt{3} - \sqrt{4}| + . . . + |\sqrt{71} - \sqrt{72}| =$
- $\sqrt{2}$
- $\sqrt{72}$
- $\sqrt{2}$
- $\sqrt{2} - \sqrt{72}$
Correct

Incorrect

Examples of questions from "Recapitulare matematică (3) clasa a VIII-a – semestrul I"

$x = \sqrt{5}, y = \frac{1}{\sqrt{5}} \Rightarrow x^{2} + y^{2} = . . .$
Inversul opusului numărului $- \frac{3}{4}$ este numărul:
$|\sqrt{2} - \sqrt{3}| + |\sqrt{3} - \sqrt{4}| + . . . + |\sqrt{71} - \sqrt{72}| =$