If the lengths of both sides of a rectangle are increased by (1/7), how much will the area of the new rectangle be increased compared to the area of the original rectangle?
若一个长方形两边长都增加它们的(1/7)，那么所得新长方形面积比原长方形面积增加多少．
<gadget id="calculator">15 / 49</gadget>
<output>15/49 = around 0.306122</output>

<result>15/49 = around 0.306122</result>