Question

x^-2/3 + 3x^-1/3 + 2 = 0

Answer 1

parentheses would be appreciated

Answer 2

(x ^{-2/3}) + (3x ^{-1/3}) + 2 =0

Answer 3

lets use a different variable yeah

Answer 4

let u=x^(-1/3) and the that means that x^(-2/3)=u^2

Answer 5

can you solve it from there?

Answer 6

I will give it a shot. Thank you for your help

Answer 7

let me know what you get, or if you need more help

Answer 8

i get u = -1, -2. When I plug them back into the equation -1 works, -2 does not
the answer is supposed to be -1, -1/8. I don't understand the -1/8

Answer 9

let me actually do the arithmetic, give me a sec

Answer 10

sorry i took so long my friend. So when you solve that quadratic you get -1 and -2. Now we have to use the orginal substituion of u=x^(-1/3). This is what you do:

u=x^(-1/3)
x=u^-3
Now we plug in our value of -1 and -2 into u^-3

x=(-1)^-3 or x=(-2)^-3
x=-1 or x=-1/8

Answer 11

thank you very very much

Answer 12

no problem