(3/7)*6-30%X=1.7.
(3/7)*6-30%X=1.7．
<gadget id="calculator">18 / 7</gadget>
<output>18/7 = around 2.571429</output>

<gadget id="calculator">(18/7) - 1.7</gadget>
<output>0.871429</output>

<gadget id="calculator">0.871429 / 0.3</gadget>
<output>2.904763</output>

<result>2.904763</result>