x to the power of 2 over 3 (2 thirds) plus 2x to the power of 1 over 3 (1 third) minus 8
2007-10-22 13:02:40 · 8 answers · asked by Jimmy_830 3 in Science & Mathematics ➔ Mathematics
x^(2/3) + 2x^(1/3) - 8 = 0
Let y = x^(1/3)
y^2 + 2y - 8 = 0
(y + 4)(y - 2) = 0
y = - 4, y = 2
Now we have
x^(1/3) = - 4 and x^(1/3) = 2
x = - 64 and x = 8
2007-10-22 13:10:02 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Solve the equation. x 2/3 - 2x 1/3 - 8 = 0
Since the middle term is an x 1/3–term, we break the x 2/3 into x 1/3 by x 1/3,
and
(x 1/3 + 2)( x 1/3 - 4) = 0,
x 1/3 + 2 = 0, x 1/3 - 4 = 0,
x 1/3 = - 2 , x 1/3 = 4.
To get back to x, let’s cube both sides of the equations.
(x 1/3 )3 = (- 2)3 , (x 1/3 )3 = (4)3 ,
Answer: x = - 8 and x = 64.
2007-10-22 13:11:48 · answer #2 · answered by JS 3 · 0⤊ 0⤋
Let y = x^1/3. The equation becomes y^2 - 2y - 8 = (y - 4)(y + 2) = 0, which gives solutions y = 4 and y = -2. So, x^1/3 = 4 and x^1/3 = -2 imply that x = 64 and x = -8.
2016-05-24 21:10:05 · answer #3 · answered by latrice 3 · 0⤊ 0⤋
x^2/3 + 2x^1/3 - 8 = 0
Let u = x^1/3
Then u^2+2u-8 = 0
(u+4)(u-2) = 0
u = - 4 and u = 2
x^1/3 = -4
x = -64
x^1/3= 2
x = 8
2007-10-22 13:10:41 · answer #4 · answered by ironduke8159 7 · 0⤊ 0⤋
X=2.666666666666666666
2007-10-22 13:52:08 · answer #5 · answered by Anonymous · 0⤊ 1⤋
-64 or 8 dude....
2007-10-22 16:25:56 · answer #6 · answered by unmaitre 2 · 0⤊ 0⤋
you know if we do ur whole hw assignment do we get credit for it? lol
2007-10-22 13:05:32 · answer #7 · answered by nogdog21 2 · 0⤊ 1⤋
true
2007-10-22 13:05:52 · answer #8 · answered by Escoffier 4 · 0⤊ 1⤋