Question

rezolvati ecuatia
Xla 4 -17Xla2 +16 =0

Answer 1

$x^{4}-17 x^{2} +16=0<=> \\ <=> x^{4}- x^{2} -16 x^{2} +16=0<=> \\ <=> x^{2} ( x^{2} -1)-16( x^{2} -1)=0<=> \\ <=>( x^{2} -1)( x^{2} -16)=0<=> \\ <=>(x-1)(x+1)(x+4)(x-4)=0=>$

=> x∈{-4; -1; 1; 4}.