Answer:

Step-by-step explanation:
The formula of the circumference of a circle is
.
The length of an arch can be found by using the ratio of circumference to the arc.
First, find the circumference of the circle:

Then you find the ratio:
The length of the arc is 90/360, which is 1/4, of the circumference.
Finally, find the length of the arc:
or 
I hope this helps :)
First, you add 1 to both sides. Then square both sides to get rid of the square root. After that you just solve it like a normal equation when you are left with 4x-2=9.
X^2 + 6x +9
(x+3) (x+3)
x+3 = 0
x = -3
answer: x=-3
The Greatest Common Factor (GCF) of 189 and 200 is 1.