Answer :
b= # of blue marbles
r= # of red marbles
r+b=27
r=3b-5
3b-5+b=27
4b-5=27
4b=32
b=8
r=3(8)-5
r=24-5
r=19
there are 8 blue marbles and 19 red
r= # of red marbles
r+b=27
r=3b-5
3b-5+b=27
4b-5=27
4b=32
b=8
r=3(8)-5
r=24-5
r=19
there are 8 blue marbles and 19 red
r=red
b=blue
r+b=27
r=3b-5
subsitute 3b-5 for r in r+b=27
3b-5+b=27
4b-5=27
add 5 to both sides
4b=32
divide both sides by 4
b=8
plug 8 for b in r+b=27
r+8=27
subtract 8 from both sides
r=19
b=8
r=19
b=blue
r+b=27
r=3b-5
subsitute 3b-5 for r in r+b=27
3b-5+b=27
4b-5=27
add 5 to both sides
4b=32
divide both sides by 4
b=8
plug 8 for b in r+b=27
r+8=27
subtract 8 from both sides
r=19
b=8
r=19