SOLUTION: Please tell me where I'm going wrong... Problem is If x-5= -8 then what is (x^2 - 5)(x^-3 - x) I got x = -3, so substituted into problem and got 9-5{1/27 -(-3)} or 4(3 and

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: Please tell me where I'm going wrong... Problem is If x-5= -8 then what is (x^2 - 5)(x^-3 - x) I got x = -3, so substituted into problem and got 9-5{1/27 -(-3)} or 4(3 and      Log On


   

Question 52357This question is from textbook Saxon Algebra 1
: Please tell me where I'm going wrong...
Problem is If x-5= -8 then what is (x^2 - 5)(x^-3 - x)
I got x = -3, so substituted into problem and got
9-5{1/27 -(-3)} or 4(3 and 1/27) or 328/27
The answer should have been 320/27
?????? Rebecca This question is from textbook Saxon Algebra 1

Found 2 solutions by Earlsdon, venugopalramana:
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
If x = -3, evaluate:
%28x%5E2-5%29%28x%5E%28-3%29-x%29 Substitute x = -3 and simplify. Watch your signs!
%28%28-3%29%5E2-5%29%28%281%2F%28-3%29%5E3%29+-%28-3%29%29
%289-5%29%28%28-1%2F27%29%2B3%29
4%28%28-1%2B81%29%2F27%29
4%2880%2F27%29
320%2F27

Answer by venugopalramana(3286) About Me  (Show Source):
You can put this solution on YOUR website!
Please tell me where I'm going wrong...
OH!POOR GIRL!YOU DID EXTREMELY WELL!!BUT SLIPEED IN THE PENULTIMATE STEP!ANY WAY IT IS VERY GOOD TO SEE YOU WORK BY YOUR SELF AND COMING OUT WITH DOUBT!KEEP IT UP!!IT WILL DO YOU A WORLD OF GOOD!
SEE MY CORRECTION AND SUGGESTIONS FOR IMPROVEMENT
Problem is If x-5= -8 then what is (x^2 - 5)(x^-3 - x)
I got x = -3, EXCELLENT
so substituted into problem and got
9-5{1/27 -(-3)}VERY GOOD,BUT A LITTLE SLIP UP?..FIRSTLY YOU BETTER PUT 9-5 IN BRACKETS AS (9-5)
AND WHEN THERE IS A - SIGN BE CAUTIOUS..WE HAVE X^-3 WHICH YOU HAVE CORRECTLY PUT AS 1/X^3..EXCELLENT ...BUT 1(-3^3)=-1/27!!!!NOT +1/27..
or 4(3 and 1/27)
4=4*80/27=320/27!!!!GOT IT DEAR?OK?ANY WAY AS I SAID BEFORE GOOD JOB!!!
or 328/27
The answer should have been 320/27
?????? Rebecca
You may edit the question. Maybe convert formulae to the same