A man has 12 coins in his pocket all of which are dimes and quarters if the total value of his change is 225 cents how many dimes and how many quarters does he have

Quarters = 7

Dimes = 5

Step-by-step explanation:

Let d = dimes and q = quarters:

d+q = 12

10d+25q = 225

Solve for d:

d = 12-q

Substitute it into the second equation:

120+15q = 225

Subtract 120 from both sides:

15q = 105

Divide by 15 in both sides

q = 7