grade 10 math
posted by Rebecca .
Chris has $3.85 in dimes and quarters. There are 25 coins in all. How many of each type of coin does he have?
If d represents the number of dimes and q represents the number of quarters, what two equations describe the problem?

Let x = # of dimes and Y = # of quarters.
10x + 25y = 3.85
x = 2/5y
Substitute 2/5y for x in first equation and solve for y. Insert that value into the second equation and solve for x. Check by inserting both values into the second equation. 
the two equation is
0.10+0.25=3.85
xy=25