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Help answering ann algebra question

jasonm123

New member
Joined
Jan 22, 2010
Messages
2
I am doing a placement study guide for my getting into college since I don't have my GED yet. I'm not so good at math much but I understand some. But anyway, I am stuck on a question for substituting values in algebraic expression. The question is If x = -3, what is the value of x^2 -1/x + 1?

Here is what I have so far and where I am stuck at. I don't know if it is correct or not:

x = -3

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

Please help with simple step by step instructions. Thanks!
 

wjm11

Senior Member
Joined
Nov 13, 2004
Messages
1,417
If x = -3, what is the value of x^2 -1/x + 1?
We need to use parentheses to show how things are grouped. From your work I think you want this:

(x^2 –1)/(x + 1)

Looks like you correctly substituted in the –3, but you didn’t simplify after that. Here it is:

((-3)^2 – 1)/(-3 + 1) = (9 – 1)/(-2) = 8/-2 = -4
 

jasonm123

New member
Joined
Jan 22, 2010
Messages
2
wjm11 said:
If x = -3, what is the value of x^2 -1/x + 1?
We need to use parentheses to show how things are grouped. From your work I think you want this:

(x^2 –1)/(x + 1)

Looks like you correctly substituted in the –3, but you didn’t simplify after that. Here it is:

((-3)^2 – 1)/(-3 + 1) = (9 – 1)/(-2) = 8/-2 = -4
Thank you so much! :D
 
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