若3xy227xy0求代数式5xy10y5x4xy2y3x的值满意采纳鼓励下亲谢谢(3xy+2)^2+|7-x-y|=0，则3xy+2=0，7-x-y=0，即x+y=7，xy=-2/3(5xy+10y)-[-5x-(4xy-2y+3x)]=5xy+10y-(-5x-4xy+2y-3x)=5xy+10y+5x+4xy-2y+3x=9xy+8x+8y=9xy+8(x+y)=9*(-2/3)+8*7=-6+56=502，4x323x427x2221过程急(4x-3)^2-(3x-4)^2=7(x-2)^2-