xIny+2y=2x^3 use implicit differentiation to find y'

xIny+2y=2x^3 use implicit differentiation to find y'
我算到是y'=6x^2*y-yIny-x/2y
但书上答案是y'=6x^2*y-yIny/x+2y
我怎麼算也算不到x在分母呢,是书错还是我错...