solve the problem using force method

Three axially loaded bars, each of length L and all constructed from a material of elasticity modulus E$,$

are arranged as shown in fig. $2.$ Two bars are connected in parallel and one of these has a

cross$-$sectional area that is twice that of the other. A third bar is connected in series at the common

point. An axial load, P$,$ is applied at the junction of the three bars. Using the displacement method,

determine $(1)$ the displacement, $d,$ of the connecting point between the three bars and $(2)$ the forces in

each of the three bars.

Fig. $2.$ Three bars in a parallel$-$series configuration