Question

subtract 7x^2+4x-9 from 5x^2+10x-5. Express the result as a trinomial in descending degree order.

Answer 1

So it's saying to 
(5x^2 + 10x - 5) - (7x^2 + 4x - 9)

Collect the like terms
and regroup

(5x^2 - 7x^2) + (10x - 4x) + ( -5 + 9)

Simplify

-2x^2 + 6x + 4

Hope this helps :)

Answer 2

after subtracting your answer should be -2x^2+6x+4