Răspuns:
Explicație pas cu pas:
a) 1/3 = x/6 ⇒ 3 x = 6×1 →produsul mezilor = produsul extremilor
3 x = 6 ⇒ x = 6 /3 ⇒ x = 2
1/3 = 2/6 → fracţii echivalente
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b) x/7 = (x+1)/8
8 × x = 7 × ( x + 1 )
8 × x = 7 × x + 7
8 × x - 7 × x = 7
x = 7
Verific:
7/7 = (7+1)/8 → fracţii echivalente
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c)
( x+1)/7 = ( 3 - 2x)/11
7 × ( 3 - 2x) = 11 ( x+1)
21 - 14x = 11 x + 11
- 14 x - 11 x = 11 - 21
- 25 x = - 10 ⇒ x = -10/-25 ⇒ x = 2/5
Verific:
( 2/5+5/5)/7 = (15/5 - 4/5)/11
(7/5)/7 = (11/5)/11
(7/5)×1/7 = (11/5)×(1/11)
1/5 = 1/5
