当X=-1/2,Y=2时[(x+1/2y)+(x-1/2y)](2x-1/2y)的值拜托各位了 3Q

问题描述:

当X=-1/2,Y=2时[(x+1/2y)+(x-1/2y)](2x-1/2y)的值拜托各位了 3Q

原式=(2x^2+1/2y^2)(2x^2-1/2y^2) =4x^4-1/4y^4 =4*1/16-1/4*16 =1/4-4 =-15/4