Solve the equation (8/21)x=(4/15), then x=how much.
解方程(8/21)x=(4/15)，则x=多少．
<gadget id="calculator">4 / 15</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">8 / 21</gadget>
<output>8/21 = around 0.380952</output>

<gadget id="calculator">(4/15) / (8/21)</gadget>
<output>7/10 = around 0.7</output>

<result>7/10 = around 0.7</result>