Let's perform the synthetic division
Divide by #1/2#
#color(white)(aaaa)##1/2##|##color(white)(aaaa)##2##color(white)(aaaa)##-15##color(white)(aaaaaa)##27##color(white)(aaaaaa)##-10#
#color(white)(aaaaaa)##|##color(white)(aaaa)##color(white)(aaaaaaa)##1##color(white)(aaaaa)##-7##color(white)(aaaaaaaa)##10#
#color(white)(aaaaaaaaa)###_________________________________________________________##
#color(white)(aaaaaa)##|##color(white)(aaaa)##2##color(white)(aaaa)##-14##color(white)(aaaaaa)##20##color(white)(aaaaaaaa)##color(red)(0)#
The remainder is #=(0)# and the quotient is #=(2x^2-14x+20)#
As the remainder #=0#, #x=1/2# is a root of #2x^3-15x^2+27x-10#
#2x^3-15x^2+27x-10=(2x^2-14x+20)(x-1/2)#