Question

02. If a^2 - a = 72, and b an n are integers such that b^n = a, which of the following CANNOT be a value for b?
(A)-8
(B) - 2
(C) 2.
(D) 3
(E) 9

note :
[tex] \bf yg \: pakai \: cara \: direport[/tex]
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Answer 1

Penjelasan:

a² – a = 72

a(a – 1) = 72

spekulation → 7 plus 2 is 9

so, let's try if a = 9

9(9 – 1) = 72

9(8) = 72 → ✔

than,

bⁿ = a → b = ⁿ√a

if n = 2,

than a = 9

the result of b is 3 or –3