第二题
4x^2-4xy-3y^2-4x-10y-3=(2x-y)^2-4y^2-4x-10y-3=(2x-y)^2-2(2x-y)+1-4y^2-8y-4=(2x-y-1)^2-(2y+2)^2=(2x+y+1)(2x-3y-3)