Gabriel has $2 worth of nickels and dimes. He has 2 more dimes than nickels. Graphically solve a system of equations in order to determine the number of nickels, x, commax, and the number of dimes, y, commay, that Gabriel has.

1 answer

To solve the problem, we need to set up a system of equations based on the information provided.

  1. Let \( x \) be the number of nickels.
  2. Let \( y \) be the number of dimes.
  3. Each nickel is worth $0.05, and each dime is worth $0.10.
  4. The total value of the nickels and dimes is $2, which we can express as: \[ 0.05x + 0.10y = 2 \]
  5. Gabriel has 2 more dimes than nickels, which we can express as: \[ y = x + 2 \]

Now we have the following system of equations:

\[ \begin{align*} 0.05x + 0.10y &= 2 \quad \text{(1)}\ y &= x + 2 \quad \text{(2)} \end{align*} \]

To solve this system, we can substitute equation (2) into equation (1).

Substituting \( y \) in equation (1): \[ 0.05x + 0.10(x + 2) = 2 \] Distributing \( 0.10 \): \[ 0.05x + 0.10x + 0.20 = 2 \] Combining like terms: \[ 0.15x + 0.20 = 2 \] Subtracting \( 0.20 \) from both sides: \[ 0.15x = 1.80 \] Dividing both sides by \( 0.15 \): \[ x = \frac{1.80}{0.15} = 12 \]

Now we know Gabriel has 12 nickels. We can find the number of dimes using equation (2): \[ y = x + 2 = 12 + 2 = 14 \]

So, Gabriel has:

  • 12 nickels (x = 12)
  • 14 dimes (y = 14)

Summary:

  • Number of Nickels (x): 12
  • Number of Dimes (y): 14

Graphical Representation:

  1. Equation (1): \( 0.05x + 0.10y = 2 \) can be rearranged to find \( y \): \[ y = 20 - 0.5x \] (This line intercepts the y-axis at 20 and has a slope of -0.5)

  2. Equation (2): \( y = x + 2 \) is a straight line with a slope of 1, intercepting the y-axis at 2.

Both these lines can be graphed on a coordinate plane, and the intersection point of the two lines will be at (12, 14). This corresponds to the solution we found algebraically.