first, let me write the expression
![(4x^3-4+7x)-(2x^3-x-8)](https://img.qammunity.org/2023/formulas/mathematics/college/rckqjc2qfyvo1z0jc24bu37od8wl55cwel.png)
So, the "-" minus before a parenthesis change the signs of the numbers that are inside, so: (and then the parenthesis can go away)
![4x^3-4+7x-2x^3+x+8](https://img.qammunity.org/2023/formulas/mathematics/college/7m2ksw5zipfn9xlba13sj43ei3eb4iqvzz.png)
now we can sum or subtract the numbers with the same x, so we can sum the 4x^3 with the -2x^3, the 7x with the x, and the -4 with the 8
so we have
![\begin{gathered} (4-2)x^3+(7+1)x+(8-4) \\ 2x^3+8x+4 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/u9nann6quqieloi37lk77rj6y5tpty89hg.png)
So the answer is: Option B