I think this is the Transitive postulate of equality.
Personally I can't see much point in giving labels to these equalities.
A. 200.625 minutes B. 184.166 minutes C. 200 minutes (round these answers like the question asked) 4. Plan A is the best because you get the most minutes for your money. I will explain my work for A, but if you need to explain the rest just ask. So, if you have to pay $3.95 every month no matter what and $0.08 for every minute you talk you can write the equation as, Cost = 3.95 + 0.08m (m stands for minutes), and the cost is 20$ then the equation is 20 = 3.95 + 0.08m, subtract 3.95 from the right side to make it 16.05 = 0.08m, then divide everything by 0.08 to get m, which gives you m= 200.625
The answer is 984.6 hope this helps
