There are two horses with a pair of saddles, the total value of the white horse with the saddle is 800 yuan, the total value of the black horse with the saddle is 600 yuan, and the total value of the two horses is 1100 yuan, then how much is the price of a black horse?
有两匹马一副鞍，白马配鞍共值800元，黑马配鞍共值600元，两匹马共值1100元，那么一匹黑马价值多少元．
<gadget id="calculator">600 - 1_100</gadget>
<output>-500</output>

<gadget id="calculator">800 + (-500)</gadget>
<output>300</output>

<gadget id="calculator">300 / 2</gadget>
<output>150</output>

<gadget id="calculator">600 - 150</gadget>
<output>450</output>

<result>450</result>