A horizontal beam $4\mathrm{.}2$ m long, resting on two simple supports $3\mathrm{.}0$ m apart, carries a uniformly distributed

load of $25k\frac{N}{m}$ between the supports with concentrated loads of $15$ kN and $20$ kN at the ends, as shown.

Assuming the weight of the beam is negligible determine the reactions Ra and Rb at the supports.

$($F$1)15$ kN

$($F$2)20$ kN

$W=25k\frac{N}{m}$

$0\mathrm{.}6$ m

$3$ m