Question

решите уравнение x^3+5x^2-4x-20=0

Answer 1

xˇ3+5xˇ2-4x-20=0
xˇ2(x+5)-4(x+5)=0
(x+5)(xˇ2-4)=0, (x+5)(x+2)(x-2)=0
a)x+5=0, x=-5
b)x+2=0, x=-2
c)x-2=0,x=2

Answer 2

X^3+5x^2-4x-20=0 X^2(x+5)-4(x+5)=0 (X^2-4)(x+5)=0 X^2-4=0. X+5=0 X^2=4. X3=-5 X1,2=+-2