Question

Buna... ma ajutati? Determinati numarul natural n care verifica egalitatile: a) n^2-3^2=4^2
b) n:(4^2)^2=1 c) 4^n+4^n-1=80

Answer 1

a)

${n}^{2} - {3}^{2} = {4}^{2}$

<=> n^2 - 9 = 16

<=> n^2 = 16 + 9

<=> n^2 = 25

<=> n ∈ { - 5, 5 }

b)

$n \div ({{4}^{2} })^{2} = 1$

<=> $n \div {4}^{4} = 1$

<=> $n = {4}^{4}$

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