Idon’t have a clue what i need to do. hurry.

-4x^2-5(x+3)+x^2

First, combine like terms.

-4x^2+x^2= -3x^2

-3x^2-5(x+3)

Distribute the 5. 

-3x^2-5x-15 <=== the simplified answer 

I hope this helps!
~kaikers

-4x^2 - 5(x+3) + x^2
Rearrange the terms so the like terms are next to each other.
-4x^2 + x^2 - 5(x+3)
Solve the like terms.
-3x^2 - 5(x+3)
Distribute.
-3x^2 -5x - 15