对数据充分性的规则还是吃不透,希望有人能解答下列题目,并适当解释。非常感谢
例1:
k^2-k=?
(1)k^2- 4k+4=0
(2)k=2
例2
x*y^2=18,则xy(x+y)=?
(1)xy=6
(2)x-y=-1
例3
x*y^2=18,则xy(x+y)=?
(1)xy=6
(2)x-y=5
例4
k^2-k=?
(1)k-1/k =1
(2)k=0.5*(1+5^(0.5))
例5
x*y^2=18,则xy(x+y)=?
(1)xy=6
(2)y*x^2+x*y^2=30
不好意思,贴错地方。呵呵
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