Question

Resolva as equações:

A- x(x+7).(x^2-5x+6)

B- x^3-7x^2+12x=0

C- x^3-x^2-9x+9=0

Answer 1

x(x+7)(x2−5x+6)

=(x(x+7))(x2+−5x+6)

=(x(x+7))(x2)+(x(x+7))(−5x)+(x(x+7))(6)

=x4+7x3−5x3−35x2+6x2+42x
resposta :
=x4+2x3−29x2+42x

x3−7x2+12x=0

x(x−3)(x−4)=0

resposta:

x=0 ou x−3=0 ou x−4=0

x=0 ou  x=3 ou x=4

x3−x2−9x+9=0

(x−1)(x+3)(x−3)=0

resposta:

x−1=0 ou x+3=0 ou x−3=0

x=1 ou x=−3 ou x=3