algebra
posted by running wild .
A university bookstore recently sold a wirebound graphpaper notebook for $2.64, and a collegeruled notebook for $3.61. At the start of spring semester, a combination of 50 of these notebooks were sold for a total of $168.86. How many of each type were sold?

Write one equation for the total number sold and another for the total money received. Each equation will have two unknowns, the number sold of each type.
Then solve the two equations in two unknowns.
There comes a time when you have to attempt these yourself. There is no time like the present. 
Here is what I got.
3.61 * 38 = 137.18
2.64 * 12 = 31.68
137.18 + 31.68 = 168.86
wire bound graph paper notebook @ 2.64
bought 12
college ruled notebook @ 3.61 bought 38
did I do this right?