Final answer:
By applying the equation a = -70m + 3200 and substituting m with 8, the predicted balance in a college student's account after 8 months of paying a $70 cell phone bill would be $2640.
Step-by-step explanation:
To predict the amount of money in a college student's account after 8 months, we can use the equation a = -70m + 3200, where a represents the account balance and m is the number of months.
Since $70 is withdrawn each month to pay for the cell phone bill, the equation reflects this constant monthly decrease from the initial $3200 balance.
Inserting 8 for m (representing 8 months) into the equation, we get:
a = -70(8) + 3200
a = -560 + 3200
a = 3200 - 560
a = 2640
After 8 months, the predicted account balance will be $2640.