此题用判别式法可得:
2x^2y+3xy+my=x+n
整理得:2yx^2+(3y-1)x+my-n=0
△=9y^2-6y+1-8y(my-n)≥0
整理得:(8m-9)y^2+(6-8n)y-1≤0
由题意得:(8m-9)y^2+(6-8n)y-1=0的两根为1/3和-1/3
由韦达定理知:(1/3)+(-1/3)=(6-8n)/(8m-9)
(1/3)*(-1/3)=-1/(8m-9)
解得:m=9/4;n=3/4