SOLUTION: A person has 30 coins consisting of dimes and quarters. The total value of the coins is $4.95. Find the number of dimes and quarters. I tried x(.25)+y(.10)=30 and x(.25)

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A person has 30 coins consisting of dimes and quarters. The total value of the coins is $4.95. Find the number of dimes and quarters. I tried x(.25)+y(.10)=30 and x(.25)      Log On


   



Question 315810: A person has 30 coins consisting of dimes and quarters. The total value of the coins is $4.95. Find the number of dimes and quarters.
I tried x(.25)+y(.10)=30
and
x(.25)+y(.10)=4.95
Neither came out quite right, so I'm not sure what I'm doing wrong. Please help. Thank you.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let d = number of dimes
Let q = number of quarters
given:
(1) d+%2B+q+=+30
.1d+%2B+.25q+=+4.95
(2) 10d+%2B+25q+=+495
Multiply both sides of (1) by 10 and
subtract (1) from (2)
(2) 10d+%2B+25q+=+495
(1) -10d+-+10q+=+-300
15q+=+195
q+=+13
and, since
d+%2B+q+=+30
d+=+30+-+13
d+=+17
The person has 17 dimes and 13 quarters