Question

ma poate ajuta cineva la 32???​

Answer 1

Răspuns:

Explicație pas cu pas:

E(x) = x²/(x⁴+x³) : [(2x+1)(x-1)-x(x-1)]/[(x+1)(2x-2)]  ; x ∈ R-{-1 ; 1 ; 0}

E(x) = x²/[x³(x+1)] : [(x-1)(2x+1-x)]/[(2(x+1)(x-1)]

E(x) = 1/[x(x+1)] : [(x+1)/[2(x+1)]

E(x) =  1/[x(x+1)] : 1/2

E(x) = 2/[x(x+1)] ; x ∈ R-{-1 ; 1 ; 0}

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E(a) = 2/[a(a+1)] ∈ Z =>

a(a+1) = ± 1 ; ±2

a(a+1) = -1  => a²+a+1 = 0 ; a ∉ Z

a(a+1) = 1 => a²+a-1 = 0 => a₁,₂ = [-1±√(1+4)]/2 ∉ Z

a(a+1) = -2 => a ∉ Z

a(a+1) = 2 => a²+a-2 = 0 => a₁,₂ = [-1±√(1+8)]/2

a₁,₂ = (-1±3)/2 => a₁ = -2 ; a₂ = 1