三道幼稚题目,送分来了!

x^2-5x+3
=[x-5/2-√13/2][x-5/2+√13/2]

x^2-(2√2)x-3
=[x-√2-√5)(x-√2+√5)

3x^2+4xy-y^2
=(x+2/3+√7/3)(x+2/3-√7/3)

[x-(5-√13)/2][x-(5+√13)/2]
[x-(√2-√5)][x-(√2+√5)]
[x-(-2-√7)/3y][x-(-2+√7)/3y]

(x-(5+√13)/2)(x-(5-√13)/2)

(x- √2 -√5)(x- √2 +√5)

(x-[(-2+√17)/3]y)(x-[(-2-√17)/3]y)

1楼第三题答案少了y

没意思，纯粹的计算问题