Re: International Space Station
Originally Posted by
lilac
->
Does anyone enjoy algebra here..
If so..what is the answer to this equation?
2x^3-3x^2+px+q = 0 substitute 3 for x 54-27+3p+q = 0 substitute -2 for x -16-12-2p+q = 0 27+3p+q = 0 -28-2p+q = 0 55+5p = 0 p=-11 q=6??
Ok this looks confusing because you wrote it all out in one line. It should look like this:
Equation
2x^3-3x^2+px+q = 0
If x = 3 then it simplifies as 54-27+3p+q = 0
which simplifies again to
27+3p+q = 0
If x = -2 then it simplifies as -16-12-2p+q = 0
which simplifies again to
-28+2p+q = 0
Since both equations in bold = 0 they are the same so we can combine and write:
27+3p+q = -28-2p+q
We can now rearrange that to:
55+5p = 0
Thus 5p = -55
p = -11
So now let's put that value of p back into those 2 bolded equations
When x = 3
27+3p+q = 0
So 27-33+q = 0, So q = 33-27
So q = 6
When x = -2
-28+2p+q = 0
So -28+22+q = 0, So q = 28-22
So q = 6
So in effect everything you posted contained the equations and the answers so I'm not sure what question you were actually asking.
You started with 1 equation with 3 unknown variables in it (x,p and q) and you looked at the cases where x=3 and x=-2
This showed that p = -11 in those 2 cases and that q must thus be 6
What further analysis were you looking for?