Question

Can anyone help me with linear algebra

Answer 1

it is hard to say if i can help if i dont know the question,

Answer 2

Well if you let's say that you have a 5X7 matrix
What is the lower dim Nul A possible?

Answer 3

is it two?

Answer 4

note first that nullity of a matrice is defined as nullity of corresponding linear transformation and what corresponds to the matrics above is a transformation from a vector space of dimension 7 to a vector space of dimensiion then by dimension theorem dimV=nullity+rank where v is the domain vector field then question reduces to max(dimV-rank) rank for linear transformations can be interpreted as maximum linealy indepent rows/columns in its corresponding representation since 5 is minimum(rows,columns) at most 5 l.indepent rows/columns can exist so if this is the case rank is 5 and since dimV=7 nullity=7-5=2