Which of the following theorems states that if a continuous beam has 'n' supports, the ends being fixed, then the same number of equations required to determine the support moments may be obtained from consecutive pairs of spans?

What is the value of maximum shear force for a simply supported beam of length 6.0 m, subjected to a uniformly distributed load (w kN/m) throughout the span, for which the bending moment equation at a section from the left support situated at 'x' m is Mx = 30x - 0.5(wx2)?

Method of joints is applicable to calculate member forces of a truss, when the number of unknown forces at the joint under consideration is not more than: