6. (4 points) Let1 2 3 47 1 0 40141 200 2 A=012 -213 2 8 - 22 -12 -12 2 Find the rank of A. (A) rank( A )=1(B) rank( A )=2 2 (C) rank( A )=3(D) rank( A )=4

9. (4 points) Let u = [-1,2] and u = [3,-5] in R2 and let T : R2 -＞ R? R? be a linear transformation such that T'(u) = [-2,1,0] and T(b)= (5,-7,1]. Let [a11 a12] A= a21 022 Q31 be the standard matrix representation of T. Which of the following is TRUE? (A)aL=0(B)az=1(C)az=-2(D)azz=1