Va rogg ajutatimaa . Va rogggg din tot sufletul meu. DAU COROANA. Am nevoie oana maine
Răspunsuri la întrebare
Răspuns:
a)
2/9 × ( - 3/4 + 27/8) = 2/9 × ( - 6/8 + 27/8) = 2/9 × ( 21/8) = 7/(3×4) = 7/12
-> am amplificat fractia 3/4 cu 2 = (3×2)/(4×2) = 6/8
-> am aflat diferenta parantezei ( - 6+27)/8 = 21/8
-> am simplificat pe 2 cu 8 = 1/4, dar si pe 21 cu 9 cu 3 =(21:3)/(9:3)=7/3
-> am inmultit fractiile 1/4 cu 7/3 =7/12 ( se inmultesc numaratorii intre ei si numitorii intre ei)
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b)
- 1/7 × 8 + ( - 1/7) = - 8/7 - 1/7 = (-8-1)/7 = - 9/7 = - 1 intreg si 2/7
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c)
- 3/10 × ( - 5/9) + ( - 1/6) = 1/6
= + (3×5)/(10×9) =
= (15/90)⁽¹⁵ =
= 1/6
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d) ( - 1 intreg si 1/5) = - ( 1×5+1)/5 = - 6/5 -> am introdus intregii in fractie
( - 3/4 + 1/8) × ( - 6/5) - ( - 5/2) × ( - 7 - 1/5) =
-> amplific fractia 3/4 cu 2 , dar si - 7/1 cu 5
= ( - 6/8 + 1/8) × ( - 6/5) - (- 5/2) × ( - 35/5 - 1/5) =
= ( - 5/8) × ( - 6/5) - ( - 5/2) × ( - 34/5) =
= 3/4 - ⁴⁾17 =
= 3/4 - (17×4)/4 =
= 3/4 - 68/4 =
= - 65/4 =
= - 16 intregi si 1/4
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e) 1 intreg si 1/3 = ( 1×3+1)/3 = 4/3 -> am introdus intregii in fractie
( - 5/6 + 1/12) × 4/3 =
= ( - 10/12 + 1/12) × 4/3=
= ( - 9/12) × 4/3 =
= - 36/36 =
= - 1
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f)
1 intreg si 1/7 = (1×7+1)/7 = 8/7
2 intregi si 1/7 = (2×7+1)/7 = 15/7 -> am introdus intregii in fractie
- 7/5 × ( 4/49 + ⁷⁾8/7) - ( - 1/18 - ²⁾1/9) × ( - 15/7) =
= - 7/5 × ( 4/49 + 56/49) - ( - 1/18 - 2/18 )×( - 15/7) =
= - 7/5 × (60/49) - ( - 3/18) × ( - 15/7) =
= - (7/49) × 60/5 - ( 1/6 ) × 15/7 =
= - ²⁾12/7 - 5/14 =
= - 24/14 - 5/14 =
= - 29/14 =
= - 2 intregi si 1/14
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g)
- 3/8 - ( - 14/25 ) × ( + 75/28) = 9/8
= - 3/8 - ( - 14/28) × ( 75/25) =
= - 3/8 + (1/2) × 3 =
= - 3/8 + ⁴⁾3/2 =
= - 3/8 + 12/8 =
= 9/8 =
= 1 intreg si 1/8
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h)
0,5 = (5/10)⁽⁵ = 1/2
0,25 = (25/100)⁽²⁵ = 1/4
13 intregi si 1/2 = (13×2+1)/2 = 27/2
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= 1/2 + 4/33 × ( - 1/4 + ²⁾27/2) =
= 1/2 + 4/33 × ( - 1/4 + 54/4 ) =
= 1/2 + 4/33 × ( 53/4) =
= ³³⁾1/2 + ²⁾53/33 =
= 33/66 + 106/66 =
= 139/66 =
= 2,1(06)
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i)
3,(2) = (32-3)/9 = 29/9
=( - 1/- 2 ) × [ 3,(2) - 5/27] =
= 1/2 × ( ³⁾29/9 - 5/27) =
= 1/2 × ( 87/27- 5/27) =
= 1/2 × ( 82/27) =
= ( 82/2) × 1/27 =
= 41/27 =
= 1,(518)
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j)
2³ = 8
3 intregi si 1/5 = ( 3×5+1)/5 = 16/5
0,625 = (625/1000)⁽¹²⁵ = 5/8
1,2 = (12/10)⁽² = 6/5
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= [ ( 2³ - 16/5 ) × 0,625 + 1,2 ] × 5/7 = 3
= [ (⁵⁾8 - 16/5) × 5/8 + 12/10 ] × 5/7 =
= [ ( 40/5 - 16/5) × 5/8 + 6/5 ] × 5/7 =
= ( 24/5 × 5/8 + 6/5) × 5/7 =
=( ⁵⁾3 + 6/5) × 5/7 =
= ( 15/5 + 6/5 ) × 5/7 =
= ( 21/5) × 5/7 =
= ( 21/7) × ( 5/5) =
= 3 × 1 =
= 3