i = 3c
i = c + 14
set both equations equal to each-other, we can
solve for c, we must.
3c = c + 14
subtract c from both sides, we must.
2c = 14
divide both sides by 2, we must.
c = 7
7 years old, Christopher is.
Ned got an overall grade of 86 percent because if each question is 4 points, then 6×4=24 but if he got a bonus 10 points, then you can do 24-10=14 and then you do 100-14 which equals your answer: 86.
The equation of a circle:

(h,k) - the coordinates of the centre
r - the radius
The midpoint of the diameter is the centre of a circle.
The coordinates of the midpoint:

(x₁,y₁), (x₂,y₂) - the coordinates of endpoints

The centre of the circle is (2,5).
The radius is the distance between an endpoint of the diameter and the centre.
The formula for distance:


The radius is 5.