180 degrees. It would be half of the circle.
        
             
        
        
        
Answer:
12. -11
13. 2
Step-by-step explanation:
12. First recall the order of operations (BEDMAS): Brackets, Exponents, Division, Multiplication, Addition, Subtraction
For question 12 there is a division and its priority is before other operations in the equation so you must divide 16/-2 first which gives you -8. 
From there because addition and subtraction is on the same level of order, you would do the question straight as it is shown (but replace 16/-2 with -8.
Your new equation is -10-8+7 = -11
13. follow the same as above using BEDMAS. It may help to look at it with additional brackets: ((-68)/(-4)) + ((5 x (-3)) 
- keep in mind there’s an addition between the two
Division and multiplication is on the same level in BEDMAS so first divide -68/-4 = 17
Second multiply 5 x -3 = -15
Now you can combine the two answers using addition: 17 + (-15) = 2
 
        
             
        
        
        
Answer: 26.5cm2
Step-by-step explanation:
 
        
             
        
        
        
Answer:
504 miles
Step-by-step explanation:
you would do 756÷12 which equals 63.... For every hour that you drive its 63 miles. Then you do 63×8 to get 504
 
        
             
        
        
        
Answer:
Step-by-step explanation:
You need to complete the square.
C(x) = 0.02(x^2 - 1000x  ...)  + 11000
C(x) = 0.02 (x^2 - 1000x + 500^2) + 11000 - 5000
C(x) = 0.02 (x^2 - 1000x + 500^2) + 6000
C(x) = 0.02(x - 500)^2 + 6000
Now if you look at the answer you will find that the square is completed. That means that number of tractors you could produce is 500 at a cost of 6000
There is a flow to this question that you may have trouble understanding.
First of all the 500^2. That comes from taking 1/2 of 1000 and squaring it. That's what you need to complete the square. 
Bur that is not what you have adding into the equation. Remember that there is a 0.02 in front of the brackets. 
500^2 = 250000 
0.02 * 250000 = 5000
So that number must be subtracted to make the square = 0. When you remove the brackets, you should get 11000 all in all.
So what you have outside the brackets is 11000 - 5000 = 6000
The rest is just standard for completing the square.