another!!! who can solve this one?

0 ⤊

another!!! who can solve this one?

(³√2x+1)+8=0

2007-09-06 15:45:06 · 3 answers · asked by EsMyNuM1 2 in Science & Mathematics ➔ Mathematics

3 answers

x= -513/2

2007-09-06 15:52:08 · answer #1 · answered by Rutgers101 2 · 0⤊ 0⤋

cuberoot(2x + 1) + 8 = 0
=> cuberoot(2x + 1) = -- 8
cubing we get
2x + 1 = -- 512
=> 2x = -- 513
=> x = -- 513/2

or if it is like
cuberoot(2x) + 1 + 8 = 0
2x = (--9)^3 = -- 729
=> x = -- 729/2

if it is like
cuberoot(2)x + 1 + 8 = 0
=> x = -- 9/cuberoot2

2007-09-06 22:56:00 · answer #2 · answered by sv 7 · 0⤊ 0⤋

re-arrange:

(2x+1)^1/3 = -8 cube both sides

2x + 1 = -8^3 = - 512

2x = -513

x = -513/2

2007-09-06 22:53:21 · answer #3 · answered by nyphdinmd 7 · 0⤊ 0⤋