grade 10 math
posted by Rebecca on .
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.