Finding x when x has different indices. How do I simplify, please?

12x^6 + 7x^4 = 9315

Forgive my inadequacies, but could somebody show the steps I need to make x the subject?

I don't know how to do this when x doesn't have the same power index.

Any help appreciated. Thanks.

Re: Finding x when x has different indices. How do I simplify, please?

Hey TheDunce.

You will have to transform this into a cubic using the transformation u = x^2 to get 12u^3 + 7u^2 - 9315 = 0 and then use the cubic formula to solve for u first and then x using the relation between x and u.

Cubic function - Wikipedia, the free encyclopedia

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Re: Finding x when x has different indices. How do I simplify, please?

Here's some information about the Cubic Formula.

Re: Finding x when x has different indices. How do I simplify, please?

Re: Finding x when x has different indices. How do I simplify, please?

Thanks for the quick replies. I will study this. I'm trying to learn from a textbook and didn't know where to start on this one.

Soroban: I've solved some quadratic equations and used the quadratic formula so I guess the comment didn't make sense. Thanks for the help.