The angle TQS is 74° and the angle SQR is 106°
 
        
             
        
        
        
(a)  
12+0.72(8)
12+5.76
17.76 qts of antifreeze
(b)
100(12+8(.72))/(12+8)
100(12+5.76)/20
100(17.76)/20
5(17.76)
88.8%
        
             
        
        
        
I'm assuming that x is part of the data set, and, with x, the mean equals 105. To find the value of x, you must add all the data values together to get 544+x (you still don't know what x equals). Then put 544+x over how many days values there are, including x (there are 6). You should have 544+x/6. Now, as this is how you would calculate the mean if you knew what x was equal to, you must set it equal to the mean, since you know what it is (105). You should now have 544+x/6 = 105. You have your equation set up--now you just have to solve it. I would multiply by 6 on both sides to get rid of the 6 on the left side. You would then have 544+x = 630. I would finally subtract 544 from both sides to get x = 86. Your final answer is x = 86.
        
             
        
        
        
Answer:
   (x, y) = (2 2/9, -1 4/9)
Step-by-step explanation:
Equate the values of y and solve for x.
   1/4x -2 = -2x +3
   (2 1/4)x = 5 . . . . . . . . add 2+2x to both sides
   x = 20/9 = 2 2/9 . . . multiply by 4/9
   y = -2(2 2/9) +3 = -4 4/9 +3 . . . . substitute for x in the second equation
   y = -1 4/9
The solution is x = 2 2/9, y = -1 4/9.