Given that a=0.76 and b=0.4, find the value of 2a+6b+0.5a-2b.
已知a=0.76，b=0.4，求2a+6b+0.5a-2b的值．
<gadget id="calculator">2.5 * 0.76</gadget>
<output>1.9</output>

<gadget id="calculator">4 * 0.4</gadget>
<output>1.6</output>

<gadget id="calculator">1.9 + 1.6</gadget>
<output>3.5</output>

<result>3.5</result>