Question 1184790

{{{Var(3X-Y) = 3}}}  ===> {{{9Var(X) + Var(Y) = 3}}}

{{{Var(X+2Y) = 5}}}  ===> {{{Var(X) + 4Var(Y) = 5}}}


===> {{{Var(X) = abs(matrix(2,2,3,1,5,4))/abs(matrix(2,2,9,1,1,4)) = 1/5}}}  and {{{Var(Y) = abs(matrix(2,2,9,3,1,5))/abs(matrix(2,2,9,1,1,4)) = 6/5}}}