Question

“Drew has 50 red, green, and blue marbles. He has six more red marbles than blue marbles and four fewer green marbles than blue marbles. Write and solve an equation to determine how many blue marbles Drew has.”

Answer 1

(1) R+G+B=50
(2) R=B+6
(3) G=B-4 so substitute G in (1)
R+B-4+B=50 substitute (2) in here
B+6+B-4+B=50 group like terms and solve
3B+2=50
3B=50-2
B=48/3=16 substitute in (2) and (3)
R=16+6=22
G=16-4=12
Check
22+12+16=50✅