If point

is on the unit ircle, then:

Since, the point is in the second quadrant, x is negative.
Thus,

Part A:

Therefore,

.
Part B:

Therefore,
The two equations graphs intersect and the points where they are touching are belonging to both graphs therefore solutions for both equations.
(2) points (x,y) are
(-1,0) (-1)^2. +0^2=1; 1=1 ✔️
0=-1+1; 0=0✔️
(0, 1). (0)^2. +1^2=1; 1=1 ✔️
1=0+1; 1=1 ✔️
first speed --- x mph
return speed -- x+16 mph
6/x + 6/(x+16) = 1
times each term by x(x+16)
6(x+16) + 6x = x(x+16)
x^2 + 4x - 96 = 0
(x-8)(x+12) = 0
x = 8 or x is a negative
her first speed was 8 mph
her return speed was 24 mph
check:
6/8 + 6/24 = 1 , that's good!
You just simplify the fraction (so, 8/6 which is 4/3)
So your comes 4(square root of 35)/ 3 (square root of 15)