Question 281508
I see a couple errors when doing this:

{{{(2x^2-5x-1)(x^2+x-3)}}}

You have the right general method in mind, but the multiplication is coming out differently. For example:

{{{2x^2 * x^2 = 2x^4}}}

You multiply the numbers in front, so {{{1 * 2 = 2}}} and it looks like you have variables down but {{{x^2 * x^2 = x^4}}} when you put them together, you get {{{2x^4}}}

Going through the rest of the problem:

{{{2x^2 * x^2 + 2x^2 * x + 2x^2 * (-3) + (-5x) * x^2 + (-5x) * x + (-5x) * (-3) + (-1) * x^2 + (-1) * x + (-1) * (-3)}}}

Which is equal to:

{{{2x^4 + 2x^3 - 6x^2 -5x^3 - 5x^2 + 15x - x^2 - x + 3}}}

Combining like terms:

{{{2x^4 -3x^3 -12x^2 + 14x + 3}}}  

That should be  your final answer! ^_^