Answer:
4 hours
Step-by-step explanation:
We can write an equation for the charge of plan 1 as follows:
C1 = 8x
Where x is the number of hours.
In the same way, we can write an equation for the charge of plan 2 as:
C2 = 12 + 5x
Where x is the number of hours.
Now, we need to find the value of x, where the charge of plan 1 is equal to the charge of plan 2, so we get:
C1 = C2
8x = 12 + 5x
Then, solving for x, we get:
8x - 5x = 12 + 5x - 5x
3x = 12
3x/3 = 12/3
x = 4
Therefore, at 4 hours the charges from the two plans are the same.