Math word problems are often is a matter of taking a moment to understand the story, and then simply writing down exactly what it says. Too many students rush or try to guess how they can shove the given numbers into some equation. Not easy and often leads to incorrect answers. Always focus first on the STORY, no the numbers - and see if the STORY is telling you how to put the numbers together, or what equation to use.
THERE ARE A TOTAL OF 216 DIMES AND QUARTERS --
Ok, so if I ADD the dimes and quarters, I will have 216 coins...
d + q = 216
IF THERE ARE 30 MORE DIMES than QUARTERS (I assume a mistype above and the word should be THAN)
Ok, so there are MORE dimes. Which means there are LESS quarters. So if I ADD 30 to the number of quarters, I should get the number of dimes. You have to think it through to get the right equation. Try to understand the story.
d = q + 30
Now I have 2 equations and 2 unknowns. I can solve by substitution, elimination or graphing. Substitution looks like the easiest choice:
If d + q = 216, and d = q +30, then (q +30) + q = 216.
I solve by combining like terms, and "doing to one side what I do to the other" to get q alone.
Good luck!
