Answer:
(D)
314 + 8s >= 518
Step-by-step explanation:
Answer: A
Just substitute a, b and c at the quadratic formula to get the answer...

Divide the numerator and denominator by 5 and get 1/12
so 5/60 simplified is 1/12
Hope this helps! :D
Answer:
399 minutes a month
Step-by-step explanation:
As I understand the question the answer would, in other words, be how many minutes you can long-distance call with the economy plan for under $30.
The unit ratio is 5 cents per minute, which equates to 20 minutes worth of call time for one dollar (100/5).
The economy plan is $20 cheaper than the deluxe plan. $20 spent on long-distance calling gets you 400 mintues, but the question asks for an integer that would still leave remaining money.
Therefore the answer is 399 minutes of long-distance calling, which would leave five unspent cents.