Help plsss its an emergency

Yahir designs bracelets. he uses between 9 and 15 red and yellow beads in the ratio of 2 red bead to 5 yellow beads. drag the beads into the container to meet these requirements

Which property was used to simplify the expression? 3c+9 +4c=3c+4c+9

The deepest part of the swimming pool is 12 feet deep.the shallowest part of the pool is 3 feet deep.what is the ratio of the deeply of the deepest part of the pool to depth of the shallowest part of a pool?