Find a least-squares solution of Ax = b by (a) constructing the normal equations for x and (b) solving for x. 1 -2 5 1 -1 2 A = b= 0 4 -4 4 5 2 a. Construct the normal equations for x without solving. X= (Simplify your answers.) b. Solve for x. X= (Simplify your answer.)