Question

aflati n :a)(2n-1)^3=125
b)n^3=2^3x3^6
c)(n-1)3=2^6x5^3
d)(4n-1)3=3^3x5)3
e)(2n+1)3=3^6x7^3

Answer 1

a) (2n - 1)³ = 125 
(2n - 1)³ = 5³
2n - 1 = 5 /+1
2n = 6 /:2
n = 3.

b) n³ = 2³ · 3⁶
n³ = 2³ · (3²)³
n³ = 2³ · 9³ 
n³ = (2 · 9)³
n³ = 18³ 
n = 18.

c) (n - 1)³ = 2⁶ · 5³ 
(n - 1)³ = 4³ · 5³
n - 1 = 20 /+1
n = 21.

d) (4n - 1)³ = 3³ · 5³
4n - 1 = 15 /+1
4n = 16 /:4
n = 4.

e) (2n + 1)³ = 3⁶ · 7³ 
(2n + 1)³ = (3²)³ · 7³
(2n + 1)³ = 9³ · 7³
2n + 1 = 63 /-1
2n = 62 /:2
n = 31.

/robertinni