Answer: 8, 21, 34, 47, 60...
Difference is 13 I added 13 each time.
16z^2-25=0
(4z)^2-(5)^2=0
This is in the form of a^2-b^2=(a+b)(a-b)
(4z)^2-(5)^2=(4z+5)((4z-5)
Hi there! The answer is 5.
As you mentioned in the question, the amount of chores Janie does is represented by c.
When we know this we can set up an expression which represents the total amount of money Janie earns.
She always receives $3.
She also receives
$2 × the amount of chores
$2 × c = 2c
The expression which represents Janie's total earnings is 3 + 2c.
Now we can start solving.
Subtract 3 from both sides.
Divide both sides by 2.
Hence, Janie must do 5 chores to earn enough money to buy a CD.