The answer is 21.
I am not sure if you're looking for the answer, or the steps... get back to me foor help.
If you need to simplify the equation it would be:

+2r-2n+7
If not sorry..
Hope This Helps!
Answer:
(B). A physical change takes place that causes molecules to move faster
Step-by-step explanation:
When a bar of chocolate melts its physical form is changed, there is no difference in its chemical composition as it is still same.
When the chocolate bar was frozen its molecules were held strongly, and they were barely moving, whereas when it melts the molecules are more free to move now.
So this is going to be alot of writing to show my thinking but ill bold the answer.
1,1
1,2
1,3
1,4
1,5
2,1
2,2
2,3
2,4
2,5
3,1
3,2
3,3
3,4
3,5
4,1
4,2
4,3
4,4
4,5
5,1
5,2
5,3
5,4
5,5
next ill mark all the ones that equal 4 or 8 when added together, with an x
1,1
1,2
x1,3
1,4
1,5
2,1
x2,2
2,3
2,4
2,5
x3,1
3,2
3,3
3,4
x3,5
4,1
4,2
4,3
x4,4
4,5
5,1
5,2
x5,3
5,4
5,5
that is 6 (that equal 4 or 8) out of 25
so your ratio would be 6:19
Answer:
Well since they're bringing 1 each day, just multiply that by the number of days of school, or just use the variable x to replace it.
1x = the number of box tops they each bring to school