factoring polynomials

[huskyGdawg]

factor: 3x(to the seventh) - 12x(to the fifth) + 5x-20x

please take me step by step... this one is different from the rest of my problems and i need help!

 

[skeeter]

already factored on the "other" board you posted it on.

 

[huskyGdawg]

this one is different because it is to the 7th power i dont know how to do those we never did those in class all the others were x^2 + x + 2 or something

 

[Mrspi]

factor: 3x(to the seventh) - 12x(to the fifth) + 5x-20x

please take me step by step... this one is different from the rest of my problems and i need help!

Just a personal note here....some of us volunteer on several of the various math help boards, and we don't take kindly to having the same question posted in multiple places...it wastes the time of volunteers.

And, are you sure you typed the problem correctly? If it is the correct problem, you can start by combining 5x - 20x:

3x<SUP>7</SUP> - 12x<SUP>5</SUP> - 15x

Now, you can remove a common factor of 3x from all three terms:

3x(x<SUP>6</SUP> - 4x<SUP>4</SUP> - 5)

I don't see anything more you can do....but there are people here who are much smarter than I am, so maybe one of them will have further suggestions.