$9 is discounted from the regular price. If you find the discounted price you get $21. Then subtract the 21 from 30 and you get 9
Answer:
When x=8, y=-6. When x=10, y=0
Step-by-step explanation:

You can plug the given y value into the second equation to get:

Hope this helps!
Answer:
3.51 for 1 day 45.63 for 13 days u could also look up what's 9% of 39 then just times it by 13
Answer:
<em>4,524 gallons</em>
Step-by-step explanation:
The volume of any cylinder is
π (radius)² (height) .
The pool's radius is 1/2 its diameter = 8 ft. So its volume is
π (8 ft)² (3 ft)
= π · (64 ft²) · (3 ft)
= π · 192 ft³
= 603.2 ft³ .
(603 ft³) · (7.5 gal / 1 ft³) = 4,524 gallons
Hope this helps :D