(2x+5)(x^2 - x - 2) how can i simplify this?

Question

explanation would be helpful

Answer 1

remember FOIL method
First
Outside
Inside Last

(2x+5)(x^2 - x - 2)
is like saying
2x(x^2-x-2)+5(x^2-x-2)
first, distribute 2x to everything inside the first ()
2x^3-2x^2-4x+5(x^2-x-2)
next, distribue the 5 to everything inside the second ()
2x^3-2x^2-4x+5x^2-5x-10
combine like terms
2x^3+(-2x^2+5x^2)+(-4x-5x)+10
2x^3+3x^2-9x+10

Answer 2

EDIT: The first answer got one thing incorrect. The +10 at the end should be a -10.

I haven't done algebra in years, so lemme see if I can get this... Multiply 2x by the three variables in the other bracket

2x^3... - 2x^2... -4x

Then multiply the 5 by the three variables...

+ 5x^2... -5x... -10

2x^3 stands alone, the +5 and -2 (x-squareds) reduce to +3x^2, the -4 and -5 (x) make -9x, and the -10 stands alone...

2x^3 + 3x^2 - 9x -10

I did it!

If you want to elongate it, (x^2 - x - 2) is the same as (x+1)(x-2)... but that's another story.