Answer:
Jeremey has saved 10 Quarters and 20 Dimes. It's time to make friends.
Step-by-step explanation:
Let D and Q stand for the numbers of Dimes(D) and Quarters(Q). Also, use pennies instead of dollars, so that 1Q = 25 and 1D = 10. It eliminates the hassle of decimal points.
From "30 coins with a total value of $4.50"
We can write that:
D + Q = 30
and that:
10D + 25Q = 450 [the value of dimes (10D) is added to the value of quarters (25Q )]
Rearrange the first equation to isolate one of the variables and then use that relationship in the second equation. I'll rearrange for D:
D = 30 - Q
10D + 25Q = 450 becomes:
10(30 - Q) + 25Q = 450
300 - 10Q + 25Q = 450
15Q = 150
Q = 10
Therefore, since D + Q = 30, we find that:
D + 10 = 30
D = 20
================================
Check the numbers:
Does
10D + 25Q = 450 ?
10(20) + 25(10) = 450 ?
200 + 250 = 450 YES
and
Does D = 30 - Q?
20 = 30 - 10 YES