SOLUTION: X^(-3)-X^(-2)-X^(-1). When X+3=1 Me and my father tried to find the answer for this problem for my brother but we couldn't figure out how to get the answer to equal 1/8, which

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: X^(-3)-X^(-2)-X^(-1). When X+3=1 Me and my father tried to find the answer for this problem for my brother but we couldn't figure out how to get the answer to equal 1/8, which       Log On


   



Question 70738: X^(-3)-X^(-2)-X^(-1). When X+3=1
Me and my father tried to find the answer for this problem for my brother but we couldn't figure out how to get the answer to equal 1/8, which is the answer the book gives us. We are looking to find out if the answer the book gives us is right or if we were just missing a step in finding the answer.

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
X^(-3)-X^(-2)-X^(-1). When X+3=1
:
x = -2
:
1%2Fx%5E3+-+1%2Fx%5E2+-+1%2Fx%5E1
:
1%2F-2%5E3+-+1%2F-2%5E2+-+1%2F-2%5E1
:
1%2F-8+-+1%2F4+-+1%2F-2
:
-1%2F8+-+1%2F4+%2B+1%2F2 = -1%2F8+-+2%2F8+%2B+4%2F8 = 1%2F8
:
How about this?