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The number of integer solutions for the syetem of inequalities 數學公式 about x is just 6，then the range of value for real number a is
（integersolutions整數解；syetem of inequalities不等式組；the range of value取值范圍）


  1. A.
    -2.5＜a≤-2
  2. B.
    -2.5≤a≤-2
  3. C.
    -5＜a≤-4
  4. D.
    -5≤a≤-4
A
分析：根據不等式的性質求出不等式的解集，根據不等式的解集找出不等式組的解集，根據已知得到-5＜2a≤-4，求出即可．
解答：，
解①得：x≥2a，
解②得：x＜2，
∴不等式組的解集是2a≤x＜2，
∵不等式組的整數解有6個，
∴-5＜2a≤-4，
∴-2.5＜a≤-2．
故選A．
點評：本題考查了解一元一次不等式（組）的應用，能求出關于a的不等式-5＜2a≤-4是解此題的關鍵．
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