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Comparati numerele rationale pozitive 2/5 si x= [1-(3/10 + 8/15) x 12/15]​

Răspuns :

Răspuns:

[tex]x = 1 - ( \frac{3 \times 3}{10 \times 3} + \frac{8 \times 2}{15 \times 2} ) \times \frac{12}{15} \\ x = 1 - ( \frac{9}{30} + \frac{16}{30} ) \times \frac{12}{15} \\ x = 1 - \frac{25}{30} \times \frac{12}{15} \\ x = 1 - \frac{5}{6} \times \frac{4}{5} \\ x = 1 - \frac{1}{3} \times 2 \\ x = 1 - \frac{2}{3} \\ x = \frac{3}{3} - \frac{2}{3} = \frac{1}{3} [/tex]

[tex] \frac{2}{5} \: \ > \: \frac{1}{3} \\ \\ \frac{2 \times 3}{5 \times 3} \: > \: \: \: \: \frac{1 \times 5}{3 \times 5} \\ \frac{6}{15} \: > \: \: \frac{5}{15} [/tex]

Răspuns:

  • x ∠ 2/5

Explicație pas cu pas:

x= [1-(3/10 + 8/15) x 12/15]  aducem la numitor comun 30

x= [1-(9/30 + 16/30) x 12/15]  adunăm fracțiile

x= 1 - 25/30 x 12/15

x = 1 - 2/3

x=3/3 - 2/3

x= 1/3

1/3 ∠ 2/5

x ∠ 2/5

1/3=5/15

2/5= 6/15