Răspuns:
Explicație pas cu pas:
x²+5x+6 = x²+2x+3x+6 = x(x+2) + 3(x+2) = (x+2)(x+3)
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E(x) = [ (3x-9)/(x²-9)] × [ ( x²+6x+9)/(x²+5x+6)]
E(x) = [ 3(x-3)/(x-3)(x+3)] × [ (x+3)²/(x+2)(x+3)]
E(x) = [3/(x+3)] × [(x+3)/(x+2)]
E(x) = 3/(x+2) ∀ x ∈ R \ { ±3; - 2}
