Mom bought 2 kilograms of apples and 2 kilograms of pears, and the total cost was 10.4 yuan. It is known that pears are 2.8 yuan per kilogram, how much is an apple per kilogram? (Solution of column equation)
妈妈买来苹果和梨各2千克，共用了10.4元．已知梨每千克2.8元，苹果每千克多少钱？(列方程解)
<gadget id="calculator">2.8 * 2</gadget>
<output>5.6</output>

<gadget id="calculator">10.4 - 5.6</gadget>
<output>4.8</output>

<gadget id="calculator">4.8 / 2</gadget>
<output>2.4</output>

<result>2.4</result>