Answer:
A. { }
Step-by-step explanation:
Absolute value cannot be less than zero.
-4 < 0
There is no solution for x, ∈, R.
Hope this helps.
Answer:
Step-by-step explanation:
AC² = AD² + DB ²
25 = AD² + 9
AD²= 25 - 9
AD² = 16
AD = 4
Area = 4*3 /2
= 6cm
Answer: 4 or 
To find the square root of a number, remember that there will be two factors that are the same that will give you the product.
Lets start from 1:
1 x 1 = 1
2 x 2 = 4
3 x 3 = 9
4 x 4 = 16
As you can see, 4 x 4 is 16. To make sure I'm correct, remember that a square roots consists two identical factors.
4 and 4 are the same numbers.
Therefore,
= 4
It can also be written as 
Answer:

will give you an explanation if you want tag me on comment.
Answer: 0.5
1) convert to I proper fraction
2) divide the fraction