Answer:
The length of the call that would cost the same with both cards is 5 minutes.
Step-by-step explanation:
Hi there!
The cost with card A can be expressed as follows:
cost A = 30 + 2 · m
Where "m" is the length of the call in minutes.
In the same way, the cost of card B will be:
cost B = 10 + 6 · m
Where "m" is the length of the call in minutes.
We have to find the value of "m" for which the call would cost the same with both cards.
Then:
cost A = cost B
30 + 2 · m = 10 + 6 · m
Subtract 10 and 2 · m to both sides of the equation:
30 - 10 = 6 · m - 2 · m
20 = 4 · m
Divide by 4 both sides of the equation:
20/4 = m
5 = m
The length of the call that would cost the same with both cards is 5 minutes.
Have a nice day!
