There is no question so this is not valid
If 33mHz doubled 3 times,
33+33=66
66+66=132
132+132=264
If

and

are mutually independent, then

and

.
If

and

are independent, then

. Ditto for

and

.
The inclusion/exclusion principle says that

Since

and

are mutually exclusive, their intersection is the empty set. It then follows that

also is the empty set, so the last probability is also 0.
Plug in what we know:

Answer:
see explanation
Step-by-step explanation:
The side of the square = x + 2, thus area is equal to
(x + 2)² ← expand using FOIL
= x² + 4x + 4
Given area = 7 then
x² + 4x + 4 = 7 ( subtract 4 from both sides )
x² + 4x = 3 ← as required