Answer:
x^3-7x^2+5x+21
Step-by-step explanation:
To simplify the expression, apply the distributive property. The distributive property states to multiply each term in each parenthesis.
x*x^2=x^3
x*-4x=-4x^2
x*-7=-7x
-3*x^2=-3x^2
-3*-4x=12x
-3*-7=21
This gives the expression x^3-4x^2-7x-3x^2+12x+21. Combine like terms and get x^3-7x^2+5x+21.
