Answer:
1) 15a - 15c + 3
2) -7n + 31 + 13m + 7p  or  13m - 7n + 7p + 31
3) 44x + 6y + 3
4) 9m - 6n + 23 
Step-by-step explanation:
1. Add like terms. 6a + 9a=15a. -8c - 7c=-15c
2. Add like terms. You can rearrange them in descending order based off of exponents and variables.
3. Multiply what's in parentheses first (distribute the 6). It should end up being (6y + 42x). Then you add like terms and put in descending order. 
4. Distribute the (-3) to what in the parentheses. It should end up being (-6n + 15 - 3m). Then you add like terms and put the expression in descending order.
 
        
             
        
        
        
Answer:
200 meters per minute
Step-by-step explanation:
12/60 since hr into minutes 
0.2 x 1000 since km and meters
 
        
             
        
        
        
Answer:
The correct answer is <u>-14</u>
Step-by-step explanation:
 
        
             
        
        
        
X=15 and Y=?
X=30 and Y=6
By rule of three
15x6/30 = 3
The answer is Y=3