Re: Word Problem
Rule #1: Name stuff.
Question #1: Name What?
Answer #1: What does it want? Name that.
M = Cost of Magazine
C = Cost of Calendar
There. After having done that, the rest is language translation. Express the problem statement in terms of these CLEAR, CONCISE, and WRITTEN definitions.
"5 magazines and 1 calendar costs 24 Euros"
5M + 1C = 24
"16 magazines and 4 calendars cost 84 euros"
16M + 4C = 84
Now the trick is to SOLVE. In this case, it's pretty easy, since C has a nice, convenient coeficient of '1'.
5M + 1C = 24 ==> C = 24 - 5M
Substitution.
16M + 4C = 84 ==> 16M + 4(24 - 5M) = 84
Can you see where to go from here?
P.S. Good call getting back at it after 20 years! Let's get to it and learn some mathematics.