Y = - 27x + 577, where x represents the number of weeks and y represents the amount of money left in her account. After how many weeks will Alma have $145 left in her account?

To solve this problem, plugin 145 where the y is located and then solve for x

y = - 27x + 577

145 = - 27x + 577

145 - 577 = - 27x

-432 = - 27x

-432/-27 = - 27x/-27

16 = x

x = 16

After 16 weeks she will have $145 dollars in her account.