已知:5x^2-2xy+y^2-4x+1=0
求:x^2y
參考答案:5x^2 - 2xy + y^2 - 4x + 1
= (x^2 - 2xy + y^2) + (4x^2 - 4x + 1)
= (x - y)^2 + (2x - 1)^2
= 0
平方和等于0 ，则每个加式等于 0
x - y = 0
2x - 1 = 0
x = y = 1/2
x^2*y = 1/8
已知:5x^2-2xy+y^2-4x+1=0
求:x^2y
參考答案:5x^2 - 2xy + y^2 - 4x + 1
= (x^2 - 2xy + y^2) + (4x^2 - 4x + 1)
= (x - y)^2 + (2x - 1)^2
= 0
平方和等于0 ，则每个加式等于 0
x - y = 0
2x - 1 = 0
x = y = 1/2
x^2*y = 1/8