I set this up as an inequality,

. If you take the cubed root of 800, you get the lower bound of the side length, which is 9.2. Then I just worked my way up until I hit the first number that put me over a volume of 800. That number is 9.29, because 9.28 cubed is 799.1 (not high enough) and 9.29 cubed is 801.8. Therefore, the bounds of the sides exist within a conjunction:

. That's the best I could come up with to help on that one. Wasn't sure if there was another method you were taught at school. I just used common sense more than any rule.
Answer:
f(x)=
1. 48x when x < or = 3,
2. 45x when 4 < or = x < or = 8
3. 42x when 9 < or = x < or = 19
4. 38x when x > 19
Step-by-step explanation:
3 boxes or less = Cost of tiles = $48
4 - 8 boxes ; cost = $45
9 - 19 boxes ; cost = $42
> 19 boxes ; cost = $38
2 is 42 but i’m not sure about one
Answer:
5:15
Step-by-step explanation:
15:55 = 3:55 in normal time
3:55 + 1 hr = 4:55
4:55 + 20 min = 5:15
Answer:
Twice a number increased by five - 2x + 5
Five decreased by twice a number- 5 - 2x
Twice the difference of a number and five- 2(x - 5)
Twice the sum of a number and five= 2(x + 5)
Five subtracted from twice a number= 2x - 5
Twice a number, less five= 2x - 5