1) 3х^3-7х^2-7х+3=0 2) х^4+5х^3+6х^2+5х+1=0

Question

1) 3х^3-7х^2-7х+3=0
2) х^4+5х^3+6х^2+5х+1=0

Answer 1

1)3х^3-7х^2-7х+3=0
(3х^3+3)-(7х^2+7х)=0
3 (х^3+1)-7х (х+1)=0
3 (х+1)(х^2-х+1)-7х (х+1)=0
(х+1)(3 (х^2-х+1)-7х)=0
(х+1)(3х^2-3х+3-7х)=0
(х+1)(3х^2-10х+3)=0
а)х+1=0
х1= -1
б)3х^2-10х+3=0
D=b^2-4ac
D=100-4×3×3=100-36=64
x2=(10+8)/6=18/6=3
x3=(10-8)/6=2/6=1/3
Ответ : х1=1;х2=3;х3=1/3