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Răspunsuri la întrebare
Răspuns:
Răspuns:
Explicație pas cu pas:
a) 4/3 = x/9 => 3 x = 4 × 9 → produsul mezilor = produsul extremilor
3 x = 36
x = 36 : 3
x = 12
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b) 2/3 = 10/x => 2 x = 3 × 10
2 x = 30
x = 30 : 2
x = 15
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c) 4/x = 8 ⇒ 8 x = 4 ⇒ x = 4/8 ⇒ x = 1/2 ∈ Q
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d) 2/x = 10/15 ⇒ 10 x = 2 × 15
10 x = 30
x = 30 : 10
x = 3
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e) x/3 = 5 ⇒ x = 3 × 5 ⇔ x = 15
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f) 3/x = 2,4 ⇒ x = 3/2,4
x = 3 : 24/10
x = 3 × 10/24
x = 30/24
x = 5/4 ∈ Q
x = 1,25
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g) x/18 = 4/9 ⇒ 9 x = 18 × 4
x = 72/9
x = 8
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h) 2 = 9/x ⇒ 2 x = 9 ⇒ x = 9/2 ∈ Q ⇔ x = 4,5
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i) 0,(15)/x = 2,5
2,5 x = 15/99
x = (5/33) : 25/10
x = (5/33) × 2/5
x = 2/33 ∈ Q
0,(15) = 15/99 = (15:3)/(99:3) = 5/33
2,5 = 25/10 = (25:5)/(10:5) = 5/2
Răspuns:
a)x×5=4×3 b)x×1=10×4 c)4×2=9×x d)3×x=9×8
x×5=12 x×1=40 8=9×x 3×x=45
×=12÷5 x=40÷1=40 x=9×8=40 ×=45÷3
x=2.4