Question 666217: If x = -3, what is the value of
x to the 7 power -1
___________________
x + 1
Answer by DrBeeee(684)   (Show Source):
You can put this solution on YOUR website! I assume you mean
(1) ((x^7) - 1)/(x+1)
and you want to know what this is when x = -3. OK?
Put x = -3 into (1) and we get
(2) ((-3)^7 - 1)/(-3+1)
Now you probable use your calculator to get (-3)^7, and you get an error, right? Sorry you can't do that, ie get a power of a negative number! You can multiply (-3) time itself 7 times or recognize that a negative number raised to an ODD power is negative!
Then (-3)^7 = -(3)^7, which you can do on your calculator to get -2187. Now continue evaluating (2) and get
(3) (-2187-1)/(-2) or
(4) (-2188)/(-2) or
(5) 1094
Answer: The value is 1094
|
|
|
