解:(2x+3y)²-(2x+y)(2x-y) =(2x+3y)²-(4x²-y²) =4x²+12xy+9y²-4x²+y² =10y²+12xy 把x=1/配并哪3,y=培码-1/2代入10y²+12xy 10y²+12xy =10*1/4+12*3分之1*负的2分蔽棚之1 =2.5-2 =0.5望采纳