### Home > INT3 > Chapter 12 > Lesson 12.1.4 > Problem 12-68

12-68.

Mary has an antique marble collection containing 40 marbles. She has five more red marbles than blue marbles and twice as many red marbles as green marbles. Write a system of equations to determine the number of each color of marble. Homework Help ✎

Let *b* = the number of blue marbles, *r* = the number of red marbles,

and *g* = the number of green marbles.

*b* + 5 = *r*

2*g* = *r**r* + *g* + *b* = 40

Solve the system of equations using a combination of substitution and elimination.