Question

8.4.9 On or off the line & Practice Problems

Answer 1

Answer:

Number of quarters → 15

Number of dimes → 2

Step-by-step explanation:

Let the number of dimes I have = y

And number of quarters = x

Since, I have amount in my pocket = $2

Therefore, 0.10y + 0.25x = 2

100(0.10y + 0.25x) = 100×2

25x + 10y = 200

5x + 2y = 40

2y = -5x + 40

y = -2.5x + 20 ---------(1)

Total number of coins in my pocket = 17

x + y = 17

y = -x + 17 ---------(2)  

By using a graphing calculator we can graph these two lines (As attached)

Solution of the given system of equations will be the point of intersection of these lines.

Solution → (2, 15)

Number of quarters → 15

Number of dimes → 2