Refer to the framing system given and given: Using Portal Method, determine the moment at fixed support at B$.$

Given:

$P1=31kN$

$P2=18kN$

$x1=5\mathrm{.}3m.$

$x2=7\mathrm{.}6m.$

$y1=4\mathrm{.}4m.$

$y2=3\mathrm{.}3m.$