Investment a starts with $1000 and increases its value by $80 each week. Investment b starts with $2000 and loses $50 of its value each week. After how many weeks will the two investments have the same value?

33.3 weeks

Step-by-step 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

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3