Question

SCRETI URMATOARELE NUMERE SUB FORMA DE CUBURI PERFECTE

a) 1, 8^2, 125, 27000, 1331, 8000, 15625
b) 2^6, 8^5, 5^12, 7^15

Answer 1

a)

1 =1³ ; 8² = (2³)² =(2²)³=4³

125 = 5 · 5 · 5 = 5³

1331 = 11 · 11 · 11 = 11³

27000= (3³ · 10 ³) = (3 ·10)³ = 30³

8000 = 20 · 20 ·20 =20³

15625 = 25 · 25 · 25 = 25³

b)

2⁶ =2²ˣ³ =( 2²)³=4³

8⁵ = (2³)⁵ = (2⁵)³ = 32³

5¹²= 5³ˣ⁴ = (3⁴)³ = 81³

7¹⁵ = 7³ˣ⁵ = (7⁵)³ = 16807³

Answer 2

a) 1 = 1³ ;  8² = (2³)² = (2²)³ = 4³ ; 125=5³ ; 27000=27*1000=3³*10³=30³ ;

    1331 = 11³ ; 8000 = 2³*10³ = 20³ ; 15625 = 5⁶=(5²)³ = 25³ ;

b)  2⁶ = (2²)3 = 4³ ; 8⁵ = (2³)⁵ = (2⁵)³ = 32³ ;

     5¹² = (5⁴)³ = 625³ ;  7¹⁵ = (7⁵)³ = 16807³