Question

Bob has $150 in his savings account and saves $40 a month

Answer 1

y = 40x + 150

Explanation:

He starts with 150.

150

He adds 40 per month. Let x represent months: so every x, he gets 40. With 2 x, he gets 80: so we multiply 40 and x and add that to his starting number.

150 + 40x

And let's represent his end amount of money with y, and set it equal.

150 + 40x = y

For the other question:

x = number of months

Bob = 150 + 40x

Andrea = 100 + 50x

100 + 50x > 150 + 40x

50x > 50 + 40x

10x > 50

x > 5

So starting month 6, Andrea will have saved more than Bob.