Answer: it will take 125 additional minutes for both costs to be equal.
Step-by-step explanation:
Let a represent the number of additional minutes that it will it take for the two to be the same.
Company A charges a flat fee of 59.99 a month and .43 additional minutes. This means that the total cost of a additional units would be
0.43x + 59.99
Company B charges 69.99 a month and .35 for additional minutes. This means that the total cost of a additional units would be
0.35x + 69.99
For the cost of the two plans to be the same, it means that
0.43x + 59.99 = 0.35x + 69.99
0.43x - 0.35x = 69.99 - 59.99
0.08x = 10
x = 125