The given equations are:
1) 2y = -x + 9 
⇒ x = 9-2y
2) 3x - 6y = -15
⇒3x = 6y - 15
x = 2y - 5
Equating the values of x, we get:
9 - 2y = 2y - 5
9 + 5 = 4y
14 = 4y
y = 3.5
Using this value of y in equation 1 we get:
x = 9 - 2(3.5) = 2
So, the solution set is (2, 3.5)
        
             
        
        
        
Answer: 
11.1803398875
Step-by-step explanation:
 
        
             
        
        
        
Answer:
66.42°
Step-by-step explanation:
Given
cos ? =  , then
 , then
? =  (
 ( ) ≈ 66.42° ( to the nearest hundredth )
 ) ≈ 66.42° ( to the nearest hundredth )