Answer:
33.3 weeks
Explanation:
Let us represent number of weeks = w
Investment a starts with $1000 and increases its value by $80 each week.
$1000 + $80 × w
1000 + 80w
Investment b starts with $2000 and loses $50 of its value each week.
$2000 - $50 × w
2000 - 50w
After how many weeks will the two investments have the same value?
1000 + 80w = 2000 - 50w
Collect like terms
80w + 50w = 2000 - 1000
130w = 1000
w = 1000/30
w = 33.333333333 weeks
Approximately
After 33. 3 weeks, the Investment will have the same value