Answer:
Step-by-step explanation:
If he has twice the number of dimes as quarters, then obviously he has more dimes than quarters. The expression that represents that is
d = 2q
That relates the NUMBER of coins; now we need one that relates the VALUE which is a dollars and cents thing. We know that the combined value of the coins is $2.70. The expression that represents this is
.1d + .25q = 2.70 because dimes are worth .10 and quarters are worth .25
Subbing the first equation into the second gives us
.1(2q) + .25q = 2.70 and
.2q + .25q = 2.70 and
.45q = 2.70 so
q = 6
This means he has 6 quarters. If the umber of dimes is twice as much, then d = 2(6) and d = 12.
He has 6 quarters and 12 dimes
