The product of 0.9 and x plus the product of 3.1 and 0.5 equals 2.45, find x.
0.9与x的乘积加上3.1与0.5的乘积等于2.45，求x．
<gadget id="calculator">2.45 - 1.55 - 1.55</gadget>
<output>-0.65</output>

<gadget id="calculator">1.55 + (-0.65)</gadget>
<output>0.9</output>

<gadget id="calculator">0.9 / 0.9</gadget>
<output>1</output>

<result>1</result>