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matematikuvol
Jan15-12, 03:26 AM
1. The problem statement, all variables and given/known data
Find x
(17-x)^2(11-x)+256-32(17-x)-64(11-x)=0


2. Relevant equations



3. The attempt at a solution
This eq has 3 solutions. I solved this by multiplication. Is this some other easier way. Perhaps to group some of the factors 17-x and 11-x. Tnx for the answer.
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution

SammyS
Jan15-12, 09:52 PM
1. The problem statement, all variables and given/known data
Find x
(17-x)^2(11-x)+256-32(17-x)-64(11-x)=0
2. Relevant equations

3. The attempt at a solution
This eq has 3 solutions. I solved this by multiplication. Is this some other easier way. Perhaps to group some of the factors 17-x and 11-x. Tnx for the answer.

I don't know of any particularly easy way. When multiplied out you have some pretty big coefficients and a very large constant term.

Use some substitution. Either of the following is suggested by the problem itself.u=17-x

v=11-xThe first takes a little less computation. It results in:u^3-6u^2-96u+640=0
The other results in a much smaller constant term.v^3+12v^2-60v+64=0

Of course if you use the substitution, t=9-x\,, you get a very simple polynomial.