[单选题]设(3(alpha_{1}-alpha)+2(alpha_{2}+alpha)=5(alpha_{3}+alpha),)试求向量`alpha=`_____，其中`alpha_{1}=(2,5,1,3)^{T},alpha_{2}=(10,1,5,10)^{T}`，(alpha_{3}=(4,1,-1,1)^{T}。)
[单选题]设(R(alpha_{1},alpha_{2},cdots,alpha_{s})=R(beta_{1},beta_{2},cdots,beta_{t})=r)，且(alpha_{1},alpha_{2},cdots,alpha_{s}和beta_{1},beta_{2},cdots,beta_{t})均为n维向量组，则下列结论正确的是(（quad）)。
