Add or subtract.

(5x^2+x-3)-(-2x^3+4)
A: -2x^3+5x^2+x+7
B: -2x^3+5x^2+x+1
C: 2x^3+5x^2+x=7
D: 2x^3+5x^2+x+1

B: -2x^3+5x^2+x+1

To add or subtract the given expression (5x^2+x-3)-(-2x^3+4), we distribute the negative sign to every term within the brackets after changing the subtraction into addition:

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

Now, we can combine like terms:

5x^2 + x - 3 + 2x^3 - 4.

Finally, we arrange the terms in descending order of the exponent of x:

2x^3 + 5x^2 + x - 3 - 4.

Simplifying further, we have:

2x^3 + 5x^2 + x - 7.

Therefore, the correct answer is D: 2x^3 + 5x^2 + x + 1.