Răspuns:
(1/2+1/3)·12/5=aducem la acelasi numitor comun termenii din paranteza
(3/6+2/6)·12/5=5/6·12/5=2 simplificam mezii cu extremii
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1/12-5/18+1/9=aducem la acelasi numitor comun 36
3/36-10/36+4/36=-3/36=-1/12
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(10/5+1/3):5/6=aducem la acelasi numitor comun termenii din paranteza
(30/15+5/15)·6/5=
35/15·6/5=7/3·6/5=42/15=14/5=2,8
1.
( 1 / 2 + 1 / 3 ) × 12 / 5 =
( 3 / 6 + 2 / 6 ) × 12 / 5 =
5 / 6 × 12 / 5 =
60 / 30 = 2
2.
1 / 12 - 5 / 18 + 1 / 9 =
3 / 36 - 10 / 36 + 4 / 36 =
- 7 / 36 + 4 / 36 =
- 3 / 36 = - 1 / 12
3.
[ 0, 5 + 0, ( 3 ) ] : 5 / 6 =
( 5 / 10 + 3 / 9 ) : 5 / 6 =
( 45 / 90 + 30 / 90 ) : 5 / 6 =
75 / 90 : 5 / 6 =
75 / 90 × 6 / 5 =
450 / 450 = 1
