Решите уравнение 2+3x(x+1)=8

Question

Решите уравнение 2+3x(x+1)=8

Answer 1

2+3х(х+1)=8
2+3х²+3х-8=0
3х²+3х-6=0
D=9+72=81

Answer 2

2+3х(х+1)=8
2+3х²+3х-8=0
3х²+3х-6=0
D=3³-4·3·(-6)=9+72=81
х₁=(-3+√81)/2·3=(-3+9)/6=1
х₂=(-3-9)/6=-12/6=-2

Comments

D=3^2-4Х3Х(-6)=9+72=81