Answer:
5 months
Step-by-step explanation:
One cellphone provider charges AED10 per month plus an activation fee of AED20.
If I used the services of this cellphone provider for x months, total charges for the services,
y = 10x + 20 --------(1)
Similarly, charges for the second cellphone provider for x months of uses will be,
y = 11x + 15 -------(2)
Input-output table for equation (1)
x 1 2 3 4 5
y 30 40 50 60 70
Input output table for equation (2)
x 1 2 3 4 5
y 26 37 48 59 70
From these tables, we find (5, 70) is a common point for both.
It reveals that after the uses of 5 months charges for both the cellphone providers will be same (y = $70)
