Question

Dau coronita,va rog din tot sufletuuuuuulll!!!❤​

Answer 1

Răspuns:

Explicație pas cu pas:

1)  

a = ( 2,3)² x ( 2.3)⁵: (2,3)⁵

     -> se scrie baza ( 2,3) si se aduna exponentii la inmultire, iar la impartire se scad

a = ( 2,3)⁽²⁺⁵⁻⁵⁾

a = (2,3)² ->  putere cu baza 2,3

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b ->  este incomplet, deoarece apare semnul impartirii, dupa (2,3)^15 : (2,3)^13 : ?

Voi afla valoarea lui ,,b" in forma postata:

b = (2,3)¹⁵ : (2,3)¹³

b = (2,3)⁽¹⁵⁻¹³⁾

b = (2,3)²   (1)

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Daca b = (2,3)¹⁵ : (2,3)¹³ : (2,3)¹, atunci valoarea lui b era:

b = (2,3)¹⁵⁻¹³⁻¹

b = (2,3)¹

b = 2,3    (2)

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c = [ (2,3)⁵]²

c = (2,3)⁵ˣ²

c = (2,3)¹⁰

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c > a = b =>   (2,3)¹⁰ > (2,3)² = (2,3)²     (1)

c > a > b:    (2,3)¹⁰ > (2,3)² > 2,3   (2)

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2).   Calculeaza:

(1 - 0,4 : 0,8 + 3 : 1,2 ) : [ (2,6 - 7/3 ×  42/49 ) × 10/7 ] =

  7/3 × 42/49 = (7/49) × 42/3 = (1/7) × 14 = 14/7 = 2

= ( 1 - 4/10 : 8/10 + 3 : 12/10 ) : [ ( 26/10 -  2 ) × 10/7 ] =

= ( 1 - 4/10  × 10/8 + 3 × 10/12 ) : [ ( 26/10 - 20/10 ) × 10/7] =

= ( 1 - 1/2  + 10/4 ) : ( 6/10  ×  10/7 ) =

= ( 2/2 - 1/2 + 5/2 ) : (6/7) =

= (6/2) × (7/6) =

= (6/6) × 7/2 =  

= 7/2 =

= 3,5

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3)

( a + b )/2 = 72 → media aritmetica a numerelor a si b

a + b = 2 × 72

a + b = 144 → suma numerelor a si b

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( b + c ) /2 = 78 → media aritmetica a numerelor b si c

b + c = 2 × 78

b + c = 156 → suma numerelor b si c

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( a + c ) / 2 = 64 → media aritmetica a numerelor a si c

a + c = 2 × 64

a + c = 128 → suma numerelor a si c

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deduc:

a + b       = 144

     b + c = 156

a     +   c = 128

_______________ adun sumele

2 × a + 2 × b + 2 × c = 144 + 156 + 128

2 × ( a + b + c ) = 428 → dublul sumei celor trei numere

a + b + c = 428 : 2

a + b + c = 214 → suma celor trei numere

Media aritmetica a celor trei numere este:

( a + b + c ) / 3 = 214 / 3 = 71,(3)

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(1/2) din 71,(3) = 35,(6)  →jumatate din media aritmetica a celor trei numere

(1/2) × ( 214)/3 = 107/3 = 35,(6)