SOLUTION: i need help to evaluate my algebra problem the problem is x2-7x-8 for x= - 3

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Question 296792: i need help to evaluate my algebra problem the problem is x2-7x-8 for x= - 3
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
There are two ways to do this:

1)

x%5E2-7x-8 Start with the given expression.


%28-3%29%5E2-7%28-3%29-8 Plug in x=-3


9-7%28-3%29-8 Square -3 to get %28-3%29%5E2=%28-3%29%28-3%29=9


9%2B21-8 Multiply


22 Combine like terms.


So x%5E2-7x-8=22 when x=-3


Or....

2)

x%5E2-7x-8 Start with the given expression.


%28x-8%29%28x%2B1%29 Factor the expression.


%28-3-8%29%28-3%2B1%29 Plug in x=-3


%28-11%29%28-2%29 Combine like terms.


22 Multiply


So again x%5E2-7x-8=22 when x=-3


You'll most likely use the first method when it comes to evaluation, but it helps to know that there are multiple ways to do it.