Answer: 
Step-by-step explanation:
 The equation of a circle in the general form is:
  
 The equaton of  a circle in standard form is:
 
Where the center is at <em>(h, k)</em> and <em>r</em> is the radius 
 To write the equation of a circle from general form to standard form, you must complete the squaare, as you can see below:
 1- Given the equation in general form:
 
 2- Complete the square:
 -Group the like terms and move the constant to the other side.
 - Complete the square on the left side of the equation.
 - Add the same value to the other side.
 Then you obtain:
 
 
        
             
        
        
        
Answer:
a = 7
b =?
c = 1/2
a + by = 0
7 + b × 1/2 = 0
7 + 1/2 b = 0
1/2 b = - 7
b = -7 × 2
b = - 14
a + by
= 7 + - 14 × 1/2
= 7 -14/2
= 7 - 7
= <u>0</u>
Step-by-step explanation:
Id.k if you forgot to write the value of b or not, since the value of b is not given, this will be ur answer.
 
        
             
        
        
        
Answer:
y= 2x+5
Step-by-step explanation:
The equation of a line is usually written in the form of y=mx+c, where m is the gradient and c is the y-intercept.
Parallel lines have the same gradient. Hence m=2.
Subst. m=2 into the equation:
y=2x +c
Now substitute a coordinate.
When x= -2, y=1,
1= 2(-2) +c
1= -4 +c
c= 1 +4
c=5
Thus, the equation of the line is y= 2x +5.