5x的2次方-12xy 9y的2次方-4x 4=0,求xy的值
问题描述:
5x的2次方-12xy 9y的2次方-4x 4=0,求xy的值
已知:5x^2-12xy+9y^2-4x+4=0,求xy的值.
答
4x^2-12xy+9y^2+x^2-4x+4=0
(2x-3y)^2+(x-2)^2=0
2x=3y x=2
y=4/3
xy=8/3