You have at least $30 in change in your drawer, consisting of dimes and
quarters. Write an inquality that shows the different number of coins in
your drawer. How do I do this?
Suppose you have X dimes. Then they are worth $.10X
Suppose you have Y quarters. Then they are worth $.25Y
Together they are worth $.10X + $.25Y
Since you have at least $30, what they are worth together must either
be equal to $30 or greater than $30, so
$.10X + $.25Y > $30
You can drop the dollar signs
.10X + .25Y > 30
If you like, you can multiply thru by 100 to remove the decimals
10X + 25Y > 3000
then you can divide thru by 5
2X + 5Y > 600
However, probably
.10X + .25Y > 30
will be sufficient.
Edwin