Answer:
See below.
Explanation:
Let d = number of dimes. Let q = number of quarters.
d + q = 35
A dime is worth 10 cents, or $0.1; d dimes are worth 0.1d.
A quarter is worth 25 cents, or $0.25; q quarters are worth 0.25q.
0.1d + 0.25q = 4.9
The system of equation is
d + q = 35
0.1d + 0.25q = 4.9