Answer:
You have
21
dimes and
7
quarters.
Step-by-step explanation:
Let
x
be the number of quarters, and
3
x
the number of dimes.
The amount of money you have can be written as
0.25
x
+
0.1
⋅
3
x
=
3.85
.
Now isolate
x
to find the number of quarters:
0.25
x
+
0.1
⋅
3
x
=
3.85
0.25
x
+
0.3
x
=
3.85
0.55
x
=
3.85
x
=
3.85
0.55
=
7
=
the number of quarters.
Then multiply by three to get the number of dimes:
7
⋅
3
=
21
7
⋅
$
0.25
+
21
⋅
$
0.1
=
$
3.85
Step-by-step explanation:
Hope this helped