The sum of 2 times x plus 30 equals 5 times x, find the value of x.
x的2倍加上30的和等于x的5倍，求x的值．
<gadget id="calculator">5 - 2</gadget>
<output>3</output>

<gadget id="calculator">30 / 3</gadget>
<output>10</output>

<result>10</result>