Question

x^4+2x^3-7x^2-8x+12=0
решите.

Answer 1

$a^4+2a^3-7a^2-8a+12=0;$
$a^4+2a^3-7a^2-8a=-12;$
$2a^{3}-8a-7a^{2}+12+a^{4}=0;$
$(a-1)(a-2)(a+2)(a+3)=0;$
$a$∈$(1; 2; -2; -3).$