The age of the elder brother this year is twice the age of the younger brother, and the age of the younger brother 5 years later is the same as the age of the elder brother 3 years ago. How old is the elder brother this year?
哥哥今年的年龄是弟弟年龄的2倍，弟弟5年后的年龄与哥哥3年前的年龄相等，则哥哥今年多少岁？
<gadget id="calculator">5 + 3</gadget>
<output>8</output>

<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">8 / 1</gadget>
<output>8</output>

<gadget id="calculator">2 * 8</gadget>
<output>16</output>

<result>16</result>