Mom bought 4 pieces of soap and 4 towels for a total of 16.8 yuan. It is known that each piece of soap is 1.9 yuan. How much is each towel? (solution by equation)
妈妈买来4块肥皂和4条毛巾共16.8元，已知每块肥皂1.9元，每条毛巾多少元？(用方程解)
<gadget id="calculator">1.9 * 4</gadget>
<output>7.6</output>

<gadget id="calculator">16.8 - 7.6</gadget>
<output>9.2</output>

<gadget id="calculator">9.2 / 4</gadget>
<output>2.3</output>

<result>2.3</result>