Answer:
feet
Step-by-step explanation:
Ones that never intersect
Apparently, the calculator at the link in your lesson is fully capable of giving you the necessary numbers. My own TI-84 work-alike gives me the account balances, but the rest of the numbers need to be figured.
In 30 years, there are 12×30 = 360 months, or 4×30 = 120 quarters. See the calculator results below. Your table can be filled in using the given information to find the contribution amount. The calculator gives the final balance. The interest amount is found by subtracting the contribution amount from the final balance.

Answer:
His equation is correct but his calculations are incorrect.
Step-by-step explanation:
180-40=140 so y=140
Hope this helps!