4. a new spiral notebook contains 30 more sheets of paper than a new memo book. the total number of sheets of paper in 3 new spiral notebooks and 5 new memo books is 810. write a system of equations can be used to find s, the number of sheets of paper in one new spiral notebook, and m, the number of sheets of paper in one new memo book.

The spiral notebook contains 30 more sheets than the memo one, so we have the first equation:
s sheets - m sheets = 30 sheets
or s - m = 30 (1)

(1) ⇒ 3s - 3m = 90

"The total number of sheets of paper in 3 spiral notebooks and 5 memo books is 810", which means we have another equation:
3*s sheets + 5*m sheets = 810 sheets
or 3s + 5m = 810.

3s - 3m = 90 
3s + 5m = 810 

From this set of equations, you can solve for s and m:
s = 120
m = 90

There are 120 sheets in a spiral notebook and 90 sheets in a memo notebook.

Hope this helps~