Answer:
Step-by-step explanation:
The two angles are formed from 2 intersecting lines. The angles are called vertically opposite angles. They are equal
4x + 21 = 85 Subtract 21
4x = 85 - 21 Combine
4x = 64 Divide by 4
x = 64/4
x = 16
Answer:

Step-by-step explanation:
We are given that endpoints of a diameter at the points (7,2) and (-9,5).
Center of the circle is the mid point of diameter
So, first find the mid point of diameter
Formula : 

Substitute the values in formula


So, center of circle = (h,k )=(-1,3.5)
To find length of diameter :




Length of radius = r = 
Standard form of the equation of the circle : 
(h,k )=(-1,3.5)

Equation of the circle : 
Equation of the circle : 
Hence the standard form of the equation of the circle with endpoints of a diameter at the points (7,2) and (-9,5) is 
Answer:
C
Step-by-step explanation:
For number 9 just take the two functions and multiply or add them I can’t tell what sign that is