One day, Yiyi Clothing Store sells two different clothes at 90 yuan each. As a result, one earns 20% and the other loses 20%. So, how much is the store owner?
依依服装店某一天将两件不同的衣服均以每件90元出售，结果一件赚20%，另一件亏20%，那么，商店老板多少
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">90 / (4/5)</gadget>
<output>225/2 = around 112.5</output>

<gadget id="calculator">(225/2) - 90</gadget>
<output>45/2 = around 22.5</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">90 / (6/5)</gadget>
<output>75</output>

<gadget id="calculator">90 - 75</gadget>
<output>15</output>

<gadget id="calculator">(45/2) - 15</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>