Question

$frac{16}{ x^{2} +1} = frac{ x^{2} }{ x^{2} +1}$

Answer 1

$frac{16}{x^2+1}= frac{x^2}{x^2+1} \ frac{16}{x^2+1}-frac{x^2}{x^2+1}=0 \ frac{16-x^2}{x^2+1}=0 \ x^2+1 neq 0 \ 16-x^2=0 \ x^2=16 \ x_1= sqrt{16}=4 \ x_2=- sqrt{16}=-4$
ОТвет: 4 и -4