Equate whats inside (arguments) 
with base period of sine function 
and solve for x to get period,
So the period of the graph of the given function is precisely 2.
Hope this helps :)
To prove that x = 2 in the equation given, first, we write the given.
(4) Given: (A) 12 - x = 20 - 5x
Then, add 5x to both sides of the equation,
(3) Addition property of equality: (B) 12 + 4x = 20
Then, subtract 12 from both sides of the equation
(2) Subtraction property of equality: (C) 4x = 8
Lastly, divide both sides by 4
(1) Division property of equality : (D) x = 2
<span>−6/11 ⋅ 3/4
= -3/11 </span>⋅ 3/2
= -9/22
hope it helps
