Four times the number A is 1 less than three times the number B. The number B is 2.6. What is the number A?
甲数的4倍比乙数的3倍少1，乙数是2.6，甲数是多少？
<gadget id="calculator">2.6 * 3</gadget>
<output>7.8</output>

<gadget id="calculator">7.8 - 1</gadget>
<output>6.8</output>

<gadget id="calculator">6.8 / 4</gadget>
<output>1.7</output>

<result>1.7</result>