A = matrix([[1,-1,-5,0],[-1,0,3,0],[0,2,4,0]]); A
A.rref()
a = vector([1,-1,0]); b = vector([-1,0,2]); c = vector([-5,3,4]); (plot(a,color='darkviolet')+plot(b,color='tomato')+plot(c,color='steelblue'))
aa = plot(3*a,color='darkviolet'); bb = plot(-2*b,start=3*a,color='tomato'); cc = plot(c,start=3*a-2*b,color='steelblue'); (aa+bb+cc).show()
d = vector([0,1,1]); B = matrix([a,b,d]).transpose(); B
B.rref()
dd = plot(d,color='steelblue'); (plot(a,color='darkviolet')+plot(b,color='tomato')+plot(d,color='steelblue'))