The price ratio of A and B is 7:3. If their prices increase by 70 yuan respectively, the price ratio is 7:4. What is the original price of A commodity?
甲、乙两种商品的价格比是7：3，如果它们的价格分别上涨70元，价格之比为7：4，甲商品原来的价格是多少元．
<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<gadget id="calculator">70 - 30</gadget>
<output>40</output>

<gadget id="calculator">40 - 10</gadget>
<output>30</output>

<gadget id="calculator">30 * 7</gadget>
<output>210</output>

<result>210</result>