Simplify : 30 – 5(15 - 10).
Apply BODMAS :
B- Brackets
O-Of
D-Division
M-Multiplication
A-Adition
S-Subtraction

Answer : D) 5
In 864 it is a tenth as large... Hope that helped lol i'm not completely sure. I did it in my head.
If we just have

that's an amplitude of 1 and a period of 
Let's modify this step by step.
Amplitude of 4. Four times the amplitude means a factor of 4 on the outside.

Period of π. Double the period means a factor of 2 on the inside.

Horizontal shift of π/2 to the left. To the left means adding a positive number to x. The question appear ambiguous. It's not clear to me if we add to x or 2x; let's make it

Vertical shift of 3:


Depending on the interpretation of the phase shift, that pi may be a pi/2.
Answer: 
Circle equation: (x - h) + (x - k) = r²
(h, k) = center
r = radius
The center is (-7, 4)
To find the radius, take the square root of 49.
√49 = 7
The radius is 7.
Best of Luck!