Solve the equation: (x-1)*2=x+2+1.
解方程：(x-1)*2=x+2+1．
<gadget id="calculator">2 + 2 + 1</gadget>
<output>5</output>

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

<gadget id="calculator">5 / 1</gadget>
<output>5</output>

<result>5</result>