5 d + 3 v = 3213
v = 4 d
substituting ... 5 d + (3 * 4 d) = 3213 ... 17 d = 3213
... solve for d , then substitute back to find v
v = 4 d
substituting ... 5 d + (3 * 4 d) = 3213 ... 17 d = 3213
... solve for d , then substitute back to find v
Let's assume the cost of one digital camera is x dollars.
According to the given information, each video camera costs 4 times as much as each digital camera. Therefore, the cost of one video camera would be 4x dollars.
Now, we are given that the cost of 5 similar digital cameras and 3 similar video cameras is $3,213.
Using this information, we can set up an equation:
5x + 3(4x) = 3213
Simplifying the equation:
5x + 12x = 3213
17x = 3213
Divide both sides of the equation by 17 to solve for x:
x = 3213 / 17
x ≈ 189
Now that we know the cost of one digital camera (x) is approximately $189, we can find the cost of one video camera:
4x ≈ 4 * 189 ≈ $756
So, the cost of one digital camera is approximately $189, and the cost of one video camera is approximately $756.
To find out how much John pays for a digital camera and a video camera, we simply add their costs:
John pays $189 (for a digital camera) + $756 (for a video camera) = $945.
Therefore, John pays $945 for a digital camera and a video camera.