Not easy:
- 4 < x^4 + 4x^2 ---> 0 < x^4+4x^2+4 = (x^2+2)^2, so it is always positive. Always satisfied. Curious ...
Now the other one:
x^4+4x^2<21 --> x^4+4x^2-21 < 0 --> (x^2+2)^2 - 25 < 0
(x^2+2)^2<25 ->>> x^2+2 < 5 ---> x^2 <3,
So -sqrt(3)<x<sqrt(3) is the answer! Brainliest?
A stem and leaf plot is a table where each of the data is divided into two parts. The stem, that is the first digit and the leaf is the last digits. Let's say that we have the following set of data.

If we want to make a stem and leaf plot of that data, we first write a column where we place the first digit of each number without repetition, like this:

These are the stems. Now the leaves are the last digit of each number put in order next to the corresponding first digit, like this:
Answer:
12)
11-5+x=2x-1
x-2x=-1-11+5
-x=-7
x=7
13)
10+2x+12=x+17
2x-x=17-12-10
x=-5
Step-by-step explanation:
Answer:
C) 
Step-by-step explanation:

Therefore, C is correct. Recall that 
The answer is D because , 4x176 = 704 which you divide by 60 because thats how many minutes are in an hour which should come out to 11 hours