Please help

. Consider the general Leontief economic equilibrium model described by A+5 = 55, which can be rearranged to (I A):E' = b. In this model, A is a matrix of internal demands (demands for the output of one sector of the economy required for production of the output of another), while 5 is a vector of external demands (6.9. the consumer demand for each sector of the economy). (a) What is the meaning, in economic terms, of the column space of (I A)? (b) What is the meaning, in economic terms, of the null space of (I A)