matlab解方程组遇到的问题 Warning:Warning,solutions may have been lost

matlab解方程组遇到的问题 Warning:Warning,solutions may have been lost Warning:Explicit solution
我用matlab来解下面方程组,
soil*0.1717+veg*0.3474+(1-soil-veg)*0.2318=b1(hang,lie)
soil*0.1643+veg*0.3160+(1-soil-veg)*0.2272=b2(hang,lie)
soil*0.5848+veg*0.4134+(1-soil-veg)*0.3993=b3(hang,lie)
其中b1,b2,b3为已导入的 150*100矩阵
代码如下
for hang=1:150
for lie=1:100
s=solve('soil*0.1717+veg*0.3474+(1-soil-veg)*0.2318=b1(hang,lie)','soil*0.1643+veg*0.3160+(1-soil-veg)*0.2272=b2(hang,lie)','soil*0.5848+veg*0.4134+(1-soil-veg)*0.3993=b3(hang,lie)');
end
end
运行程序后发现结果是空的,发现s =[ empty sym ],并且有如下警告
Warning:Warning,solutions may have been lost
Warning:Explicit solution could not be found.
> In solve at 140
In linest at 28
请问这是怎么回事呢?