A student does 25 math problems, and gets 4 points for 1 correct answer, no points for no answer, and 1 point deducted for 1 wrong answer. He has not done 3 questions and got 73 points. Ask him how many questions he answered correctly. (Solution of column equation)
一个学生做25道数学题，答对1题得4分，不答不给分，答错1题倒扣1分．他有3道题未做，得73分，问他共答对了几道题．(列方程解)
<gadget id="calculator">73 - 3</gadget>
<output>70</output>

<gadget id="calculator">25 + 70</gadget>
<output>95</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">95 / 5</gadget>
<output>19</output>

<result>19</result>