Janelle is in charge of bringing in dry erase markers for everyone in her math group to use to work on a project. She brings 3 m
arkers for each person in her group and 5 extra markers for everyone to share. If Janelle brings in 23 markers in all, which equation represents the information? Let x represent the number of students in Janelle’s group.
3x = 23 + 5
3x = 23
3x – 5 = 23
3x + 5 = 23
x = number of students in her group, which is some positive whole number.
3x = number of markers for all the students in her group, since each person gets 3 markers.
3x+5 = adding on an extra 5 markers to the previous count.
That last expression represents the number of markers Janelle brings, which is 23, so that's how we end up with 3x+5 = 23
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Extra info (optional section):
If you wanted to solve that equation, then subtract 5 from both sides to get 3x = 18. Dividing both sides by 3 leads to x = 6. There are 6 students in her group. Since each gets 3 markers, they'll take 3*6 = 18 markers total. Adding on that additional 5 gets us to 18+5 = 23.
