The polynomial

has a unique root,

, for any

.
Hence

is a polynomial with roots

and
as the function is polynomial domain exist for all real number ie (-infinity to + infinity) but range exist (0 to +infinity ) due to modulus negetive range do not exist
The given expression is :
2xx+3-5(x-2)
We know that, 

Aleena expands 2xx+3-5(x-2) as 2x²+3-5x-10. She is mistaken because the sign before 10 should be +10 instead of -10. Hence, the correct expanded form is 2x²+3-5x+10. Hence, this is the required solution.