There are 30 coins inside a jar. Some of the coins are dimes and the rest are quarters. The total value of the coins is $3.20. How do you write a system of equations for this situation?
1 Answer
Jul 12, 2018
-
quantity equation:
#" "d + q = 30# -
value equation:
#" "0.10d + .25q = 3.20#
Explanation:
Given:
Define variables:
Let
In these types of problems there are always two equations:
-
quantity equation:
#" "d + q = 30# -
value equation:
#" "0.10d + .25q = 3.20#
If you prefer working in pennies (no decimals), your second equation becomes:
Use substitution or elimination to solve.