Use the information to find a linear algebraic equation model to use to answer the question being asked.

Question

Mark and Don are planning to sell each of their marble collections at a garage sale. If Don has
2
more than
4
times the number of marbles Mark has, how many does each boy have to sell if the total number of marbles is
127
?

Answer 1

Let's say Mark has M marbles and Don has D marbles.  So from the information given:

 

D = 4M + 2

D + M = 127

 

Now substitute and solve.

 

4M + 2 + M = 127

5M + 2 = 127

5M = 125

M = 25

D = 127 - M = 127 - 12 = 102

 

So Mark has 25 marbles and Don has 102.