$1.$ For the structure shown in the image, determine the reactions and internal forces using the flexibility method.

As indicated in a$)$ and b$).$

a$)$ Release the vertical external link at node A$.$

b$)$ Release the vertical external link at node B$.$

$2.$ For the same structure as above, determine the vertical deflection where the load P is applied.

a$)$ Find the moment diagram of the $$real$$ hyperstatic beam.

b$)$ Define the virtual beam as the one shown at the end and find the associated moment diagram $($the beam is isostatic$).$

c$)$ Establish the equality between virtual work and virtual internal energy to find the displacement sought.

Thank you.