Question

Subtract and simplify answer.

Answer 1

`(s^2+5st-9t^2)-(2s^2-2st+2t^2)=\\\\=s^2+5st-9t^2-2s^2+2st-2t^2=\\\\=s^2-2s^2-9t^2-2t^2+5st+2st=\boxed{-s^2-11t^2+7st}`

Answer 2

-s^2+7st-11t^2

Explanation:

s^2 +5st - 9t^2 - ( 2s^2 -2st +2t^2)

Distribute the minus sign

s^2 +5st - 9t^2 - 2s^2 +2st -2t^2

Combine like terms

-s^2+7st-11t^2