Answer:

Step-by-step explanation:
The depth function is:

After 3 minutes, a submarine had descended to −320 feet.
This means that
. So


After 8 minutes, the submarine had descended to −420 feet.
This means that
. So


From the first equation:

So





And

So

Let the third side = x.
The sum of any two sides must be greater than the third side
14 + 9 > x
23 > x
14 + x > 9
x > -5
9 + x > 14
x > 5
So 5 < x < 23
Answer:
EF= 24
Step-by-step explanation:
= 24
Answer:
≥≤ are used when the number is less/greater or equal than some thing.
>< are used when a number is strictly less/greater than some thing.
1) a number x is less than 0 or at least 3
A number x is less than 0 is written as: x < 0.
x is at least 3 is written as: x ≥ 3.
Then we can write the statement as:
x < 0 ∨ x ≥ 3.
where ∨ means "or"
2) a number x is less than or equal to 4 and greater than -1
x less than or equal to 4 is written as: x ≤ 4
x is greater than -1 is written as: x > - 1.
We can write the statement as:
-1 < x ≤ 4
3) a number x is less than 8 and greater than or equal to 5
x is less than 8 is written as: x < 8
x is greater than or equal to 5 is written as: x ≥ 5.
Then the statement can be written as:
5 ≤ x < 8,