19/4x方+5/2xy-2/3y方-(-5/4x方-1/6xy+3/4y方)这题有点复杂,

问题描述:

19/4x方+5/2xy-2/3y方-(-5/4x方-1/6xy+3/4y方)这题有点复杂,

19/4x^2+5/4x^2+5/2xy+1/6xy-2/3y^2-3/4y^2
=6/x^2+8/3xy-17/12y^2