Answer:
-2
Step-by-step explanation:
3n+2n+4=9n+12
5n+4=9n+12
5n-9n=-4+12
-4n=8
n=8/-4
n= -2
 
        
             
        
        
        
Answer:Well, I don't know what you got so I can't tell you if it is right. 
If it works in both equations, it depends of whether your equations are set up correctly.
 
Here is how I would do this problem.
Let x = no. of hot dogs,y = number of sodas.
First equation is just about the number of things.
x + y = 15
Second equation is about the cost of things.
1.5 x + .75 y = 18
 
solve x+y = 15 for y  y = 15-x    substitute into second equation
1.5x + .75(15 - x) = 18    
 
You should get the correct answer for number of hot dogs if you solve this correctly.  Put your answer in the x + y =15 equation to get y.  Then put both x and y into the cost equation and check your answer.
 
Hope this helps.
Step-by-step explanation:
 
        
             
        
        
        
Answer:
C
Step-by-step explanation:
 
        
             
        
        
        
Answer:
312
Step-by-step explanation:
Since the ratio is 7:8, mark it as 7x:8x. 
Now, they said that the first length is 273. Solve the equation:
7x=273
x=39
Substitute it into 8x. 39*8=312. That's your answer.
PLS MARK BRANILIEST!!!