Column formula calculation: the ratio of A and B is 3:4, subtract B from A to get (5/14), find B.
列式计算：甲乙两数的比是3：4，乙数减甲数得(5/14)，求乙数．
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<result>5/7 = around 0.714286</result>