Re: How do I solve this?


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Posted by Denis Borris on September 25, 2002 at 16:51:35:

In Reply to: How do I solve this? posted by Jim on September 25, 2002 at 08:46:18:

: x(x^3 + 98) = x^2(2x - 73) - 1176

that stupidoo equation becomes:
x^4 - 2x^3 - 73x^2 + 98x + 1176 = 0

I'm "rusty", so I went at it in this lumberjack fashion:

we can assume (I guess) that the factoring looks like:
(x^2 ....)(x^2 .......)

To get 2x^3, then we need 2x, since (x^2 * 2x) = 2x^3; so:
(x^2 ...)(x^2 ... 2x ...)

To get 98x, that 2x is multiplied by 49, since (2x * 49) = 98x; so:
(x^2...49)(x^2 ... 2x ...)

And since 1176 / 49 = 24, then:
(x^2 - 49)(x^2 - 2x - 24) = 0

x^2 - 49 = 0; so x = 7 or -7

Use quadratic on x^2 - 2x - 24 = 0 to get x = 6 or -4




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