Find all the solutions of 0=x^3+2x^2-5x

Question

Find all solutions of 

x=

a=

b=

c=

      .

Answer 1

First factor out an x

x(x²+2x-5)=0 So one solution is x=0.

concentrating on x²+2x-5 = 0, we use the quadratic equation, (-b±√(b²-4ac))/2a

x = (-2 ± √(4-4(1)(-5)))/2 = -1 ± √(4+20))/2 = -1 ± 2√6/2 = -1 ±√6 --> x = -1 +√6, -1 -√6

for x=

a=-1

b=1

c=6

Answer 2

factor (x)(x^2 + 2x -5)

set each factor = 0 and solve for x

x=0 and

x= -b/2a + or - (2/2a)sqr(b^2 - 4ac) with a=1, b=2 and c=-5

x= -1 + or - (1/2)sqr(4+20) = -1 + or - sqr6

3 solutions for x

cubic equations have 3 solutions