Answer:
23 
Step-by-step explanation:
we are given that angle NRQ is 78 degrees
we can see from the figure that the sum of the given angles is angle NRQ
so 
(8x + 7) + (4x - 1) = 78
12x + 6 = 78
12x = 72
x = 6
Now, we have to find angle PRQ
replacing x with 6 in the equation of angle PRQ
PRQ = 4(6) - 1
PRQ = 23
 
        
             
        
        
        
Answer:
r=0.5 or 1/2
Step-by-step explanation:
if you multiply 0.5 to each Xs you can find out why r is 0.5
 
        
             
        
        
        
2a+1b=27.50
4a+2b=59.50
Multiply first equation by -4 and the second by 2 so you can drop off the a values then add the equations together.  Then solve for b.  You should get b=6.
Then plug b into one of the original equations and solve for a and you should get 10.75
So a plate of spaghetti is $10.75 and a salad is $6.
<em><u>Please mark brainliest!</u></em>
 
        
             
        
        
        
Answer:
D
Step-by-step explanation:
Circumference = Pi * radius^2
The radius is half of the diameter, 23.
 
        
                    
             
        
        
        
Answer:
49
Step-by-step explanation: no idea i just evaluated like that