Resposta:
65-
a) ( 8 / 5 )³ = 8/5 * 8/5 * 8/5 =  512/ 125

b) (4/7)^4 = 4/7* 4/7* 4/7 * 4/7 = 256/2401

c) ( 1/6)^2 = 1/6 * 1/6 = 1/ 36

d) ( 2/5)^4 = 2/5 * 2/5 * 2/5 * 2/5 = 16/625

66-

(3/4)² = (3/4) ( 3/4) = 9/16

(1/3)^5 = ( 1/3) * ( 1/3) * ( 1/3) * ( 1/3) * ( 1/3) = 1/243

( 5/7)^3 = (5/7) * (5/7) * (5/7) = 125/343

(2/9)^4 = (2/9) * (2/9) * (2/9) *(2/9) = 16/6561

(6/5)² = 6/5 * 6/5 = 36/25

(7/8)^3 = 7/8 * 7/8 * 7/8 = 343/ 512

Explicação passo a passo:

65-
a) ( 8 / 5 )³ = 8/5 * 8/5 * 8/5 =  512/ 125

b) (4/7)^4 = 4/7* 4/7* 4/7 * 4/7 = 256/2401

c) ( 1/6)^2 = 1/6 * 1/6 = 1/ 36

d) ( 2/5)^4 = 2/5 * 2/5 * 2/5 * 2/5 = 16/625

66-

(3/4)² = (3/4) ( 3/4) = 9/16

(1/3)^5 = ( 1/3) * ( 1/3) * ( 1/3) * ( 1/3) * ( 1/3) = 1/243

( 5/7)^3 = (5/7) * (5/7) * (5/7) = 125/343

(2/9)^4 = (2/9) * (2/9) * (2/9) *(2/9) = 16/6561

(6/5)² = 6/5 * 6/5 = 36/25

(7/8)^3 = 7/8 * 7/8 * 7/8 = 343/ 512

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