9a-ab+5b
9(2)-(2)(7)+5(7)
18-14+35
39
Answer: a. Radius of circle = 
b. The equation of this circle :
Step-by-step explanation:
Given : Center of the circle = (3,10)
Circle is passing through (12,12).
a. To find the radius we apply distance formula (∵ Radius is the distance from center to any point ion the circle.)
Radius of circle = 
Radius of circle = 
i.e. Radius of circle = 
b. Equation of a circle =
, where (h,k)=Center and r=radius of the circle.
Put the values of (h,k)= (3,10) and r=
, we get
∴ The equation of this circle :
Answer: x^2 - 14x + 49
Explanation:
1) Divide the coefficient of x by 2:
14 / 2 = 7
2) so you have to add 7^2 = 49
x^2 - 14x + 49
3) that trinomial is equivalent to:
=> (x - 7)^2
4) prove that using the formula (a - b)^2 = a^2 - 2ab + b^2
(x - 7)^2 = x^2 - 14x + 49
Then you have to add 49 to complete the square. and form a perfect square trinomial.