Answer:
A
Explanation:
You have to simplify the brackets in turn.
3 times x^3- 7x+1 = 3x^3- 21x+ 3
then do 3 times x + 4= 3x + 12
you then add them all together, if they have a power add them, if they just have an x add them, and if they are just a number add them.
So it goes to 3x^3- 24x - 9,
this is because 3x^3 cant be added/ subtracted by anything, -24x is made from -21x- 3x, and -9 is made from 3 - + 12, so this means 3 - 12 = -9.
I hope this helps, have a lovely day.