Posted by Jason on Wednesday, July 1, 2009 at 7:41pm.
April buys eight books for $44. Paper back books cost $4 and hard back books cost $8. How many of
each book did she buy?

Math  Marina, Wednesday, July 1, 2009 at 8:39pm
4 paper backs and 4 hard cover

Math  Ms. Sue, Wednesday, July 1, 2009 at 8:42pm
Hmm  that's not right.
4 * 4 = 16
4 * 8 = 32
16 + 32 = 48.
Ooops! 
Math  MathMate, Wednesday, July 1, 2009 at 9:30pm
For this kind of problem, I usually start off with all paperbacks, thus 8*4=$32.
Since I am short 4432=$12, and changing from a paperback to a hardcover costs 84=$4, So I must have bought 3 hardcovers and 83=5 paperbacks.
Check: 3*8+5*4=24+20=$44. 
Math  DrBob222, Wednesday, July 1, 2009 at 10:46pm
And then there's the LONG way of doing it.
H = number of hard covers.
P = number of paper covers.
===========================
H + P = 8
8H + 4P = 44.
================
Two equations in two unknowns. Solve for H and P.