# Can someone help me fast?

• Apr 27th 2005, 04:17 AM
island_chic
Can someone help me fast?
I need help answering these problems. If anyone can help me it would be greatly appreciated! Thank you!

Solve the Equation
1.x^2/3+5X^1/3+4+0
A.plus or minus 3i and plus or minus square root of 3
B. 3, square root of 3
C. plus or minus 3, plus or minus i square root of 3
d.plus or minus 3

2.If f(x)+2x^2+x and g(x)+2x-l, what is [f o g](x)?
A.2x^2-7x+6
B. 2x^2-7x+8
C. 2x^2-3x+2
D. x^2-3x+6
• Apr 27th 2005, 04:21 AM
island_chic
Anybody? :confused:
• Apr 27th 2005, 10:54 AM
ticbol
Some of reasons why nobody wants to solve your problems here:
1. The two poblems are not clear. The are no spaces to separate the terms.
2. You used "+" for the equal sign "=".
3. You showed 4 possible answers per problem, like multiple choice, but none of them are correct. Either those are your own solutions, or you copied the wrong solutions for the two problems.

If i understood your intention, then,

1.x^2/3+5X^1/3+4+0

I assume you mean
x^(2/3) +5x^(1/3) +4 = 0

Let y = x^1/3, so,
y^2 +5y +4 = 0
(y+4)(y+1) = 0

y+4 = 0
y = -4
Changing back to y = x^(1/3),
x^(1/3) = -4
Raise both sides to their 3rd power, or cube them,
x = (-4)^3 = -64

y+1 = 0
y = -1
x^(1/3) = -1
x = (-1)^3 = -1

Therefore, x = -64 or -1. ........answer.

------------------------
2.If f(x)+2x^2+x and g(x)+2x-l, what is [f o g](x)?

I assume you mean
iF f(x) = 2x^2 +x, and g(x) = 2x -1, what is [f o g](x)?

[f o g](x) = 2(2x -1)^2 +(2x -1)
= 2(4x^2 -4x +1) +2x -1
= 8x^2 -8x +2 +2x -1