Cannot proceed beyond a point

[gamaz321]

Hello,
I got this problem where I could get the x value after simplyfying. However, I cannot manipulate the given expression to utilize the x value.
I would appreciate any help on this. Thanks.

 

[Dr.Peterson]

Hello,
I got this problem where I could get the x value after simplifying. However, I cannot manipulate the given expression to utilize the x value.
I would appreciate any help on this. Thanks.

Why not just plug it in? You could find the square, cube, and so on; or use a method that just requires repeated multiplication, if you have learned that.

You might carry out the polynomial division before doing so.

And it might help to find a quadratic of which x is a zero.

But what you've done so far is correct, if that helps.

 

[Cubist]

Hello,
I got this problem where I could get the x value after simplyfying. However, I cannot manipulate the given expression to utilize the x value.
I would appreciate any help on this. Thanks.

Is this question part of an exercise in which the other questions all simplify in some specific way?

Can you please check the last term in the numerator, is it a "23" because it's quite hard for me to read it
[math] \dfrac{x^4 - 6x^3 - 2x^2 + 18x + 23} { x^2 - 8x + 15 } [/math]You could factor the denominator but (as it is written above) nothing cancels with the numerator

 

[gamaz321]

Yes, it is 23. Sorry about that.

 

[gamaz321]

Why not just plug it in? You could find the square, cube, and so on; or use a method that just requires repeated multiplication, if you have learned that.

You might carry out the polynomial division before doing so.

And it might help to find a quadratic of which x is a zero.

But what you've done so far is correct, if that helps.

Thanks for the advice. Plugging in would be quite a labor-intensive exercise. I am trying to figure out if it can be done in a shorter way.

 

[Deleted member 4993]

Thanks for the advice. Plugging in would be quite a labor-intensive exercise. I am trying to figure out if it can be done in a shorter way.

I don't see any shorter way. Before that excercize, I would make sure that the coefficients and the 'signs' are correct.

 

[gamaz321]

OK thanks.

 

[Dr.Peterson]

Thanks for the advice. Plugging in would be quite a labor-intensive exercise. I am trying to figure out if it can be done in a shorter way.

It isn't hard at all, if you do what I suggested. Have you tried at all?

Do the division first, and you'll have no power higher than x^2, and you already know what that's equal to. And when you evaluate it, the denominator turns out to be very simple. (I saw this when I did what I suggested and found a quadratic of which x is a zero.)

Just try! Sometimes that's the best trick -- at the least, it will reveal things about the problem.

 

[gamaz321]

Thanks for the advice. I tried and got it!