The number of science books purchased by the school library is (3/7) that of story books. The total number of science books and story books purchased is 1500. How many science books are purchased? (can be solved by equation)
学校图书馆购进科技书的册数是故事书的(3/7)，购进的科技书和故事书共1500册，购进科技书多少册？(可以用方程解答)
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 + (3/7)</gadget>
<output>10/7 = around 1.428571</output>

<gadget id="calculator">1_500 / (10/7)</gadget>
<output>1_050</output>

<gadget id="calculator">(3/7) * 1_050</gadget>
<output>450</output>

<result>450</result>