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kx^2-18x+8=0,求kkx^2-18x+8=0文字表述:k乘以x的平方减去18x加8等于0,求k=?原题:kx^2-18x+8=0hasonesolutiontwiceasbigastheother,whatisthevalueof不知道原句确切意思是什么~

题目详情
kx^2-18x+8=0,求k
kx^2-18x+8=0
文字表述:k乘以x的平方减去18x加8等于0,求k=?
原题:kx^2-18x+8=0 has one solution twice as big as the other,what is the value of 不知道原句确切意思是什么~
▼优质解答
答案和解析
k为9
设解为x,2x(因为one solution twice as big as the other)
则,根据韦达定理得
3x=18/k
2x^2=8/k
解得
k=9