Xiaohua reads a book. On the first day, he reads more (1/4) than on the second day. On the second day, he reads 50 pages less than on the first day. He just finished reading it in two days. How many pages does this book have?
小华读一本书，第一天比第二天多读(1/4)，第二天比第一天少读50页，两天正好读完，这本书共有几页？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) - 1</gadget>
<output>-3/4 = around -0.75</output>

<gadget id="calculator">1 + (-3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">50 / (1/4)</gadget>
<output>200</output>

<gadget id="calculator">1 + (1/4) + 1</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">200 * (9/4)</gadget>
<output>450</output>

<result>450</result>