Solve the equation: 3x-(2/5)*(3/4)=(9/5).
解方程：3x-(2/5)*(3/4)=(9/5)．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(2/5) * (3/4)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">9 / 5</gadget>
<output>9/5 = around 1.8</output>

<gadget id="calculator">(3/10) + (9/5)</gadget>
<output>21/10 = around 2.1</output>

<gadget id="calculator">(21/10) / 3</gadget>
<output>7/10 = around 0.7</output>

<result>7/10 = around 0.7</result>