方程lgx=8-2x的根x∈（k，k+1），k∈Z，则k=______．
令f（x）=lgx+2x-8，则方程lgx+2x-8=0的近似解x=x0∈（k，k+1），k∈Z，即 函数f（x）的零点，
在（k，k+1）上，k∈Z，
∵f（3）=lg3+6-8＜0，f（4）=lg4+8-8＞0，
∴函数f（x）的零点在（3，4）上，
∴k=3，
故答案为3．
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| We have two new students l our class. Their 2 are Lucy and Lily. They are twins (双胞胎). They look the same (一样). They 3 American. They are 4 the same row. This is a picture 5 our classroom. This is 6 desk and that is 7 chair. Where are 8 _ bags? They are behind the chairs. Look! 9 that under the chair. Is it a hat? 10 , it's a cat. | ||||
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