Hola

a)

(5/2x-x^3+2x^4):(x+1/2)

..2.x^4..-x^3..0x^2 + (5/2)x + 0 |..x+(1/2)

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

.........-2.x^3

..........2.x^3+.x^2

...................x^2+.(5/2)x

..................-x^2 -(1/2)x

..........................2.x

.........................-2.x..-1

*****************************

.............................-1

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

(2 x^3 - 2 x^2 + x + 2)(x + (1/2)) - 1

b)((1/3) x^3 + x^2 - 6):(-3x^2 + x - 7)

((1/3) x^3 + x^2 - 6)....|(-3x^2 + x - 7)

-(1/3)x^3+(1/9)x^2-(7/9)x......-(1/9)x-(10/27)

...........(10/9)x^2.-(7/9)-6

...........(-10/9)x^2+(10/27)x-(70/27)

.........................-(11/27).x -(70/27)

Entra en este video, te lo explican muy bien, yo lo aprendi de esta forma!

https://www.youtube.com/watch?v=inuImtZHQjo

soy un asco con los números .-.

Te deseo suerte!