The equation a = 50m + 100 represents the amount of money in Malorie’s bank account as a function of time, in months. The table shows the amount in Katina’s bank account for a period of several months.
Month 0 1 2 3 4 5
Katina's Bank Account 200 220 240 260 280 300

A. How much money is in Malorie’s bank account when Katina has $280 in her account? Show your work.

B. Whose account changes at a greater rate? Show your work.