Answer:
64 weeks
Step-by-step explanation:
Given that you already have $400 saved and you save $50 per week, in x weeks, you would have saved:
400 + (50 * x)
Also, given that Mr Brierley has $2000 in his bank account and he saves $25 per week, in x weeks, he would have:
2000 + (25 * x)
You and Mr Brierley would have the same amount of money when:
400 + (50 * x) = 2000 + (25 * x)
Solving for number of weeks, x, we have:
400 + 50x = 2000 + 25x
Collecting like terms:
50x - 25x = 2000 - 400
25x = 1600
x = 1600 / 25
x = 64
Hence, it will take 64 weeks for you and Mr Brierley to have the same amount of money.