Hello,
It is all linear so assuming the second red force from the left is at the quarter point of the cross beam then 3/4 of the force is resisted at the nearest end and 1/4 at the farthermost end. Then assuming that cross beam meets the middle of the supporting beams, those reactions are split half and half on each green support.
Continue for each red force. Sum the resulting reactions and at the end check that the sum of your reactions is equal to the sum of your fitting forces.
Alternatively for each load in turn take moments about each support in turn.