1. The problem statement, all variables and given/known data The problem is quite easy, but I've still trouble solving this. Given the two base vectors e1=(1,-2,0) and e2=(0,3,0) and the other ones of a different vector space w1=(1,0,0) and w2=(0,1,0). I've to find a matrix A that that does the following Ae1=w1 and Ae2=w2 2. The attempt at a solution Easy isn't it? I've done what the professor did to solve such problems: Calculate: e1=1*w1+(-2)*w2 and: e2=0*w1+3*w2 thus that shouls yield the matrix A:(1, 0, 0; -2, 3, 0; 0, 0, 0) where ; is written for different lines in the matrix A. But if I calculate A*e1 I get something totally wrong. Where's the mistake in my calculation?