Question

Aflați valoarea expresiei:
a) [6,75-4,5×1 2/3]×[-1 1/3]³
d) [-5/12-13/20]²×[-1 13/32]
c) [-11/18+[-2 2/9]×(-0,2)]³×(-1,2)​

Answer 1

Răspuns:

Explicație pas cu pas:

a) [6,75-4,5×1 2/3]×[-1 1/3]³ = ?

1 2/3 = (1·3+2)/3 = 5/3

1 1/3 = (1·3+1)/3 = 4/3

[6,75-4,5×1 2/3]×[-1 1/3]³ = [675/100 - 45/10 · 5/3] · (-4/3)³ =

= (27/4 - 9/2 · 5/3)·(-64/27) = (³⁾27/4 - ²⁾45/6)·(-64/27) =

= (81-90)/12 · (-64/27) = (-9)·(-64) / (12·27) = 576/324⁽⁹ = 64/36⁽⁴ =

= 16/9

d) [-5/12-13/20]²×[-1 13/32] = ?

1 13/32 = (1·32+13)/32 = 45/32

[-⁵⁾5/12-³⁾13/20]²×[-1 13/32] = [(-25-39)/60]²· (-45/32) =

= (-64/60)²· (-45/32) = (-16/15)²·(-45/32) = 256·(-45) / (225·32) =

= -256 / (5·32) = - 8/5

c) [-11/18+[-2 2/9]×(-0,2)]³×(-1,2)​ = ?

2 2/9 = (2·9+2)/9 = 20/9

c) [-11/18+[-2 2/9]×(-0,2)]³×(-1,2)​ = [-11/18 - 20/9 ·(-2/10) ]³·(-12/10) =

= [-⁵⁾11/18 + 40/90 ]³ ·(-12/10) = [(-55+40)/90]³·(-12/10) =

= (-15/90)³·(-12/10) = (-1/6)·(-12/10) =12/60 = 1/5

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