Answer:

Step-by-step explanation:
The formula of a volume of a sphere:

R - radius
We have R = 3 ?. Substitute

If the radius is 30, then the volume is:

If 30 is the length of diameter, then the radius R = 30 : 2 = 15.
Therefore the volume:

X rays=E
Microwaves=A
Gamma rays=C
Radio waves=F
Infrared waves=D
Ultraviolet waves=B
Answer:
The square root function
sqrt(144) or √144 produces a single positive value, 12.
However if you have an equation
x² = 144, then you have two possible values for x, 12 and -12.
Two ways to look at it.
x² - 144 = 0
Difference of two squares
(x+12)(x-12) = 0
x = -12, 12
x² = 144
x = ±√144
x = ±12
x = -12, 12