2x - 3 / 2x^4 - 9x^3 + 21x^2 - 26x + 12

I got 2x³-12x²+3x-21.5 when usuing long division to solve the equation:

(2x⁴-9x³+21x²-26x+12)/(2x-3)

 

Fisrt you need the value of x in (2x-3) to change from 2 to one, and you obviously get that from dividing by 2 which will give you (x-3/2). Then you use long division to do the rest.