Mathematical Problem

2b&lt;=2.5<a
















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2007-07-09 19:46:15 補充：
唔知點解出唔到ｄ字2b&lt;=2.5&lt; a2b&lt;=2.52(2x-7 over 4)&lt;=2.52x-7 over 2&lt;=2.52x-7&lt;=52x&lt;=5+72x&lt;=12x&lt;=62.5&lt; a2.5&lt; x+4 over 37.5&lt; x+43.5&lt; xrange of x is 3.5&lt; x&lt;=6自己再check check，如果仲係唔明，就問同學or老師=]

2b &lt;= 2.5 and a &gt; 2.5
(2x - 7)/2 &lt;= 2.5 and (x+4)/3 &gt; 2.5
2x - 7 &lt;= 5 and 2(x+4) &gt; 15
2x &lt;= 12 and 2x &gt; 7
x &lt;= 6 and x &gt; 3.5

so, 3.5 &lt; x &lt;= 6