$(a)\;(x^{2}+x-1)y=(1+ylogy)x\qquad(b)\;(x^{2}+x+1)y=(1+ylogy)x\qquad(c)\;(x^{2}+x-1)y=(1+ylogy)x\qquad(d)\;(x^{2}+x+1)y=(1-ylogy)x$