若4x²-4x+9y²-12y+5=0,求(x-3y)²-(x+3y)²
问题描述:
若4x²-4x+9y²-12y+5=0,求(x-3y)²-(x+3y)²
答
4x²-4x+9y²-12y+5=0,
==>(2x-1)^2+(3y-2)^2=0
x=0.5;y=2/3
(x-3y)²-(x+3y)²=-6xy-6xy=-12xy=-4