6(7)^2+4(7)+8=y
6(49)+28+8=y
294+28+8=y
330=y
Easy peasy
the midpoint between

and

is

just average them
so given that (3,5) is the midpoint of (-4,5) and (x,y)

so by logic

and

times both sides by 2 for everybody
-4+x=6 and 5+y=10
add 4 to both sides for left one and minus 5 from both sides for right
x=10 and y=5
the coordinate of point C is (10,5)
the x coordinate is 10
CALCULATE 5/8 + 3 1/4 x -3/6 - 2 5/12 = -3 5/12
<span>Length of outer track = sum of length of 10 pieces = circumference of the outer circle
if R is the Radius of outer circle then...
Circumference of the outer track = 2pi*R
Similarly the circumference of the inner track (with radius r) = 2pi*r
length of each outer piece is 3.4 inch more than length of inner piece
So total outer length is 10*3.4 =34 inches more than the inner length.
=> Outer Circumference - Inner Circumference = 34 inches
=> 2pi*R - 2pi*r = 34
=> 2pi(R -r) = 34
=> R-r = 34/2pi = 5.41 inches
=> R-r = Width of the track = 5.41 inches</span>