Raymond B. answered 09/01/22
Math, microeconomics or criminal justice
x^6 +9x^3 -5 = 0
set w =x^3
resulting quadratic equation is:
w^2 +9w -5 =0
w =-9/2 +/-(1/2)sqr(81+20)
= about .525 or -9.525
w=x^3
x=cube root of w = about (.525)^1/3, (-9.525)^1/3
x = about 0.807 and -2.120
it's a 6th degree equation, which has 6 solutions, the other 4 are imaginary
x=.525^1/3. there are 3 cube roots, 2 imaginary, 1 real
x= -.5((-9+sqr1010)/2)^1/3 + .5((-9+sqr101)/2)(sqr3)i
and one more imaginary solution
then same with x=(-9.525)^1/3, 1 real, 2 imaginary solutions