At vero eos et accusamus et iusto odio dignissimos ducimus qui blanditiis praesentium voluptatum deleniti atque corrupti quos dolores et quas molestias excepturi sint occaecati cupiditate non provident, similique sunt in culpa qui officia deserunt mollitia animi, id est laborum et dolorum fuga. Et harum quidem rerum facilis est et expedita distinctio. Nam libero tempore, cum soluta nobis est eligendi optio cumque nihil impedit quo minus id quod maxime placeat facere possimus, omnis voluptas assumenda est, omnis dolor repellendus. Itaque earum rerum hic tenetur a sapiente delectus, ut aut reiciendis voluptatibus maiores alias consequatur aut perferendis doloribus asperiores repellat.
x^3 is not a parabola ...
let x = u-4/3 perhaps for a subsitution .... unless your good at factoring
might need to bea u+4/3
|dw:1378843200116:dw| Graph would look like this and as amistre64 said it's not a parabola. Then again, I don't think you need a graph for solving the equation.
x^3 - 4x^2 - 25x + 100 (x^3 - 4x^2) - (25x - 100) seems factorable to me
sorry, it's a polynomial, a cubic function to be more accurate. It has three 'zero' values. I know that the zeros are at -5, 4, and 5 because I looked at a graphing calculator; I have no Idea how to get there though. (x^3 - 4x^2) - (25x - 100) x^2 (x - 4) - 25 (x - 4) <- pretty sure I'm not doing this right At least I'm winding up with 4 as one of my zeros... even if it's two of them... How do I proceed?
since you know that (x-4) is one of the solution, try long division.
or, try this: \[x^2 (x-4) - 25x + 100\]
with long division I wound up with x^2 - 25, no remainder
\[x^2 ( x - 4 ) + 25 ( x + 4 )\] okay, so there's two of the values.
which gives you (x+5)(x-5) since it's a perfect square...so your solutions are (x+5), (x-5), and (x-4)
from the long division...
so if the last value is a perfect square, you can just simplify it down? where are you getting the x in (x-5) from?
you did fine factoring, but you need to undistribute (factor again really) the (x-4) \[x^2 ( x - 4 ) - 25 ( x - 4 )\] \[(x-4)~(x^2 - 25)\] from here we should be bale to see that when x=4, then x-4 goes to zero and when x = 5 or -5, then x^2-25 goes to zero